U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Congressional research reportDec 14, 2021
Ask Donna
What actually matters in this document.
Text
U.S. Strategic Nuclear Forces:
Background, Developments, and Issues
Updated December 14, 2021
Congressional Research Service
https://crsreports.congress.gov
RL33640
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Summary
Even though the United States has reduced the number of warheads deployed on its long-range
missiles and bombers, consistent with the terms of the 2010 New START Treaty, it is also
developing new delivery systems for deployment over the next 10-30 years. The 117th Congress
will continue to review these programs, and the funding requested for them, during the annual
authorization and appropriations process.
During the Cold War, the U.S. nuclear arsenal contained many types of delivery vehicles for
nuclear weapons. The longer-range systems, which included long-range missiles based on U.S.
territory, long-range missiles based on submarines, and heavy bombers that could threaten Soviet
targets from their bases in the United States, are known as strategic nuclear delivery vehicles. At
the end of the Cold War, in 1991, the United States deployed more than 10,000 warheads on these
delivery vehicles. With the implementation of New START completed in February 2018, the
United States is limited to 1,550 accountable warheads on these delivery vehicles, a restriction
that will remain in place through February 2026, while New START Treaty remains in force.
At the present time, the U.S. land-based ballistic missile force (ICBMs) consists of 400 landbased Minuteman III ICBMs, each deployed with one warhead, spread among a total of 450
operational launchers. This force is consistent with the New START Treaty. The Air Force has
modernized the Minuteman missiles, replacing and upgrading their rocket motors, guidance
systems, and other components, so that they can remain in the force through 2030. It has initiated
a program to replace these with a new Ground-based Strategic Deterrent beginning around 2029.
The U.S. ballistic missile submarine fleet currently consists of 14 Trident submarines. Each can
carry 20 Trident II (D-5) missiles—a reduction from 24 missiles per submarine—with the total
meeting the launcher limits in the New START Treaty. The Navy converted 4 of the original 18
Trident submarines to carry nonnuclear cruise missiles. Nine of the submarines are deployed in
the Pacific Ocean and five are in the Atlantic. The Navy also has undertaken efforts to extend the
life of the missiles and warheads so that they and the submarines can remain in the fleet past
2020. It has designed and is beginning production of the new Columbia class submarine that will
replace the existing fleet beginning in 2031.
The U.S. fleet of heavy bombers includes 20 B-2 bombers and 40 nuclear-capable B-52 bombers.
The B-1 bomber is no longer equipped for nuclear missions. This fleet of 60 nuclear-capable
aircraft is consistent with the U.S. obligations under New START. The Air Force has begun to
retire the nuclear-armed cruise missiles carried by B-52 bombers, leaving only about half the B52 fleet equipped to carry nuclear weapons. The Air Force plans to procure both a new long-range
bomber, known as the B-21, and a new long-range standoff (LRSO) cruise missile during the
2020s. DOE is also modifying and extending the life of the B61 bomb carried on B-2 bombers
and fighter aircraft and the W80 warhead for cruise missiles.
The Obama Administration’s review of the size and structure of the U.S. nuclear force, and a
subsequent review of U.S. nuclear employment policy, advised the force structure that the United
States has deployed under the New START Treaty. The Trump Administration completed its
review of U.S. nuclear forces in February 2018, and reaffirmed the basic contours of the current
U.S. force structure and the ongoing modernization programs. The Trump Administration also
deployed a new low-yield warhead on Trident II (D-5) missiles. The Biden Administration started
its review of U.S. nuclear posture in July 2021 and plans to complete this review in early 2022.
Congress will review plans for U.S. strategic nuclear forces and will likely assess the costs of
these plans in the current fiscal environment.
Congressional Research Service
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Contents
Introduction ..................................................................................................................................... 1
Background: The Strategic Triad..................................................................................................... 3
Force Structure and Size During the Cold War ......................................................................... 3
Force Structure and Size After the Cold War ............................................................................ 4
Current Force Structure and Size .............................................................................................. 7
Strategic Nuclear Delivery Vehicles: Post-Cold War Reductions and Current
Modernization Programs ............................................................................................................ 10
Intercontinental Ballistic Missiles (ICBMs) ........................................................................... 10
Peacekeeper (MX) ............................................................................................................ 10
Minuteman III ................................................................................................................... 10
Minuteman Modernization Programs ............................................................................... 13
Ground-Based Strategic Deterrent (GBSD) ...................................................................... 17
Minuteman III Life Extension as an Alternative to GBSD ............................................... 21
W87-1 Warhead ................................................................................................................ 23
Submarine-Launched Ballistic Missiles .................................................................................. 25
The SSGN Program .......................................................................................................... 25
The Backfit Program ......................................................................................................... 26
Basing Changes................................................................................................................. 26
Warhead Loadings ............................................................................................................ 27
Modernization Plans and Programs .................................................................................. 28
The Columbia Class Submarine........................................................................................ 33
Bombers .................................................................................................................................. 37
B-1 Bomber....................................................................................................................... 37
B-2 Bomber....................................................................................................................... 38
B-52 Bomber..................................................................................................................... 41
B-21 Bomber..................................................................................................................... 46
Sustaining the Nuclear Weapons Enterprise............................................................................ 49
Issues for Congress ........................................................................................................................ 52
Force Size ................................................................................................................................ 52
Force Structure ........................................................................................................................ 55
Debate About the Need for a Triad ................................................................................... 55
Debate About Specific Legs of the Triad .......................................................................... 56
Debate About Low-Yield Weapons................................................................................... 58
The Cost of Nuclear Weapons ................................................................................................. 60
Figures
Figure 1. U.S. Strategic Nuclear Weapons: 1960-1990 ................................................................... 3
Figure 2. U.S. Strategic Nuclear Forces: 1991-2020 ....................................................................... 5
Tables
Table 1. U.S. Strategic Nuclear Forces Under START I and START II .......................................... 6
Table 2. U.S. Strategic Nuclear Forces under New START ............................................................ 8
Congressional Research Service
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Contacts
Author Information........................................................................................................................ 62
Congressional Research Service
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Introduction
During the Cold War, the U.S. nuclear arsenal contained many types of delivery vehicles for
nuclear weapons. These included short-range missiles and artillery for use on the battlefield,
medium-range missiles and aircraft that could strike targets beyond the theater of battle, shortand medium-range systems based on surface ships, long-range missiles based on U.S. territory
and submarines, and heavy bombers that could threaten Soviet targets from their bases in the
United States. The short- and medium-range systems are considered nonstrategic nuclear
weapons and have been referred to as battlefield, tactical, and theater nuclear weapons. The longrange missiles and heavy bombers are known as strategic nuclear delivery vehicles.
In 1990, as the Cold War was drawing to a close and the Soviet Union entered its final year, the
United States had more than 12,000 nuclear warheads deployed on 1,875 strategic nuclear
delivery vehicles.1 As of July 1, 2009, according to the counting rules in the original Strategic
Arms Reduction Treaty (START), the United States had reduced to 5,916 nuclear warheads on
1,188 strategic nuclear delivery vehicles.2 Under the terms of the 2002 Strategic Offensive
Reduction Treaty (known as the Moscow Treaty) between the United States and Russia, this
number was to decline to no more than 2,200 operationally deployed strategic nuclear warheads
by the end of 2012. The U.S. Department of State reported that the United States had reached that
level, with only 1,968 operationally deployed strategic warheads in December 2009.3 The New
START Treaty, signed by President Obama and Russia’s President Medvedev on April 8, 2010,
reduced those forces further, to no more than 1,550 warheads on deployed launchers and heavy
bombers.4 According to the U.S. Department of State, on September 1, 2021, the United States
had 1,389 warheads on 665 deployed ICBMs, SLBMs, and heavy bombers, within a total of 800
deployed and nondeployed ICBMs, SLBMs, and heavy bombers.5
Although these numbers do not count the same categories of nuclear weapons, they indicate that
the number of deployed warheads on U.S. strategic nuclear forces has declined significantly in
the decades following the end of the Cold War. Yet, nuclear weapons continue to play a key role
in U.S. national security strategy, and the United States does not, at this time, plan to either
eliminate its nuclear weapons or abandon the strategy of nuclear deterrence that has served as a
core concept in U.S. national security strategy for more than 60 years. In a speech in Prague on
April 5, 2009, President Obama highlighted “America’s commitment to seek the peace and
security of a world without nuclear weapons.” But he recognized that this goal would not be
reached quickly, and probably not in his lifetime.6 And, even though President Obama pledged to
1 Natural Resources Defense Council. Table of U.S. Strategic Offensive Force Loadings. Archive of Nuclear Data.
http://www.nrdc.org/nuclear/nudb/datab1.asp. The same source indicates that the Soviet Union, in 1990, had just over
11,000 warheads on 2,332 strategic nuclear delivery vehicles.
2 Russia, by the same accounting, had 3,909 warheads on 814 delivery vehicles. See U.S. Department of State, Bureau
of Verification, Compliance and Inspection. Fact Sheet. START Aggregate Numbers of Strategic Offensive Weapons.
October 1, 2009. Washington, DC.
3 U.S. Department of State, Bureau of Public Affairs, The Nuclear Nonproliferation Treaty: Promoting Disarmament,
Washington, DC, April 27, 2010, http://www.state.gov/documents/organization/141497.pdf.
4 The parties are to meet this limit within seven years of entry-into-force, which could occur in early 2011. For more
information on the New START Treaty, see CRS Report R41219, The New START Treaty: Central Limits and Key
Provisions, by Amy F. Woolf.
5 U.S. Department of State, Bureau of State, Bureau of Arms Control, Verification, and Compliance, New START
Treaty Aggregate Numbers of Strategic Offensive Forces, Fact Sheet, Washington, DC, https://www.state.gov/newstart-treaty-aggregate-numbers-of-strategic-offensive-arms/.
6 The White House, Office of the Press Secretary, Remarks by President Obama, Prague, Czech Republic, April 5,
Congressional Research Service
1
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
reduce the roles and numbers of U.S. nuclear forces, the 2010 Nuclear Posture Review noted that
“the fundamental role of U.S. nuclear weapons, which will continue as long as nuclear weapons
exist, is to deter nuclear attack on the United States, our allies, and partners.”7 Moreover, in the
2010 NPR and in the June 2013 Report on the Nuclear Employment Guidance of the United
States,8 the Obama Administration indicated that the United States would pursue programs that
would allow it to modernize and adjust its strategic forces so that they remained capable in
coming years.
The Trump Administration emphasized its continuing support for the U.S. nuclear arsenal in the
Nuclear Posture Review released on February 2, 2018. This document noted that “the current
threat environment and future uncertainties now necessitate a national commitment to maintain
modern and effective nuclear forces, as well as the infrastructure needed to support them.”9 The
report not only reaffirmed the basic contours of the current U.S. force structure and the ongoing
modernization programs, it also called for the development of a new low-yield warhead for
deployment on Trident II (D-5) missiles.
The Biden Administration, in its Interim National Security Strategic Guidance, indicated that the
United States would “take steps to reduce the role of nuclear weapons in our national security
strategy, while ensuring our strategic deterrent remains safe, secure, and effective and that our
extended deterrence commitments to our allies remain strong and credible.”10 The Administration
is in the process of conducting its nuclear posture review and has continued to request funding for
each of the ongoing nuclear modernization programs (described below) in its budget request for
FY2022.11
Most Members of Congress have supported the general contours of U.S. nuclear posture. While
some programs have been open to scrutiny, Congress has continued to support funding for most
aspects of the ongoing modernization programs. Nevertheless, questions about the costs of these
programs, and the trade-offs they might require within the defense budget, surfaced after
Congress passed the Budget Control Act in 2011 and have continued to animate debate during the
annual authorizations and appropriations process. Congress may again address questions about
the costs of the nuclear modernization programs, the rationale for some of the programs, and the
possible trade-offs with other defense priorities, as the Pentagon absorbs the costs of responding
to the Covid-19 crisis and possibly alters its procurement and readiness priorities.
This report reviews the ongoing programs that will affect the expected size and shape of the U.S.
strategic nuclear force structure. It begins with an overview of this force structure during the Cold
War, and summarizes the reductions and changes that have occurred since 1991. It then offers
details about each category of delivery vehicle—land-based intercontinental ballistic missiles
(ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers—focusing on their
current deployments and ongoing and planned modernization programs. The report concludes
2009, https://obamawhitehouse.archives.gov/the-press-office/remarks-president-barack-obama-prague-delivered.
7 Department of Defense, Nuclear Posture Review, Washington, DC, April 6, 2010, p. 15, https://dod.defense.gov/
Portals/1/features/defenseReviews/NPR/2010_Nuclear_Posture_Review_Report.pdf.
8 https://apps.dtic.mil/dtic/tr/fulltext/u2/a590745.pdf.
9 Department of Defense, Nuclear Posture Review, Washington, DC, February 2, 2018, p. 2, https://media.defense.gov/
2018/Feb/02/2001872886/-1/-1/1/2018-NUCLEAR-POSTURE-REVIEW-FINAL-REPORT.PDF.
10 The White House, Interim National Security Strategic Guidance, Washington, DC, March 2021, p. 13,
https://www.whitehouse.gov/wp-content/uploads/2021/03/NSC-1v2.pdf.
11 Kingston Reif, “Biden Continues Trump Nuclear Funding,” Arms Control Today, July/August 2021.
https://www.armscontrol.org/act/2021-07/news/biden-continues-trump-nuclear-funding#.YN-N_siC2nY.twitter.
Congressional Research Service
2
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
with a discussion of issues related to decisions about the future size and shape of the U.S.
strategic nuclear force.
Background: The Strategic Triad
Force Structure and Size During the Cold War
Since the early 1960s the United States has maintained a “triad” of strategic nuclear delivery
vehicles. The United States first developed these three types of nuclear delivery vehicles, in large
part, because each of the military services wanted to play a role in the U.S. nuclear arsenal.
However, during the 1960s and 1970s, analysts developed a more reasoned rationale for the
nuclear “triad.” They argued that these different basing modes had complementary strengths and
weaknesses. They would enhance deterrence and discourage a Soviet first strike because they
complicated Soviet attack planning and ensured the survivability of a significant portion of the
U.S. force in the event of a Soviet first strike.12 The different characteristics might also strengthen
the credibility of U.S. targeting strategy. For example, ICBMs eventually had the accuracy and
prompt responsiveness needed to attack hardened targets such as Soviet command posts and
ICBM silos, SLBMs had the survivability needed to complicate Soviet efforts to launch a
disarming first strike and to retaliate if such an attack were attempted,13 and heavy bombers could
be dispersed quickly and launched to enhance their survivability, and they could be recalled to
their bases if a crisis did not escalate into conflict.
Figure 1. U.S. Strategic Nuclear Weapons: 1960-1990
Source: Natural Resources Defense Council, Archive of Nuclear Data.
12 Department of Defense. Annual Report to Congress, Fiscal Year 1989, by Frank Carlucci, Secretary of Defense.
February 18, 1988. Washington, DC, 1988. p. 54.
13 In the early 1990s, SLBMs also acquired the accuracy needed to attack many hardened sites in the former Soviet
Union.
Congressional Research Service
3
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Figure 1 displays the increases in delivery vehicles and warheads in the U.S. force structure
between 1960, when the United States first began to deploy ICBMs, and 1990, the year before the
United States and Soviet Union signed the first Strategic Arms Reduction Treaty (START).
According to unclassified estimates, these numbers grew steadily through the mid-1960s, with the
greatest number of delivery vehicles, 2,268, deployed in 1967. The number then held relatively
steady through 1990, at between 1,875 and 2,200 ICBMs, SLBMs, and heavy bombers. The
number of warheads carried on these delivery vehicles increased sharply through 1975, then, after
a brief pause, again rose sharply in the early 1980s, peaking at around 13,600 warheads in 1987.
The sharp increase in warheads in the early 1970s reflects the deployment of ICBMs and SLBMs
with multiple warheads, known as MIRVs (multiple independent reentry vehicles). In particular,
the United States began to deploy the Minuteman III ICBM, with 3 warheads on each missile, in
1970, and the Poseidon SLBM, which could carry 10 warheads on each missile, in 1971.14 The
increase in warheads in the mid-1980s reflects the deployment of the Peacekeeper (MX) ICBM,
which carried 10 warheads on each missile.
In 1990, before it concluded the START Treaty with the Soviet Union, the United States deployed
a total of around 12,304 warheads on its ICBMs, SLBMs, and heavy bombers. The ICBM force
consisted of single-warhead Minuteman II missiles, 3-warhead Minuteman III missiles, and 10warhead Peacekeeper (MX) missiles, for a total force of 2,450 warheads on 1,000 missiles. The
submarine force included Poseidon submarines with Poseidon C-3 and Trident I (C-4) missiles,
and the Ohio-class Trident submarines with Trident I, and some Trident II (D-5) missiles. The
total force consisted of 5,216 warheads on around 600 missiles.15 The bomber force centered on
94 B-52H bombers and 96 B-1 bombers, along with many of the older B-52G bombers and 2 of
the new (at the time) B-2 bombers. This force of 260 bombers could carry over 4,648 weapons.
Force Structure and Size After the Cold War
During the 1990s, the United States reduced the numbers and types of weapons in its strategic
nuclear arsenal, both as a part of its modernization process and in response to the limits in the
1991 START Treaty. The United States continued to maintain a triad of strategic nuclear forces,
however, with warheads deployed on ICBMs, SLBMs, and bombers. According to the
Department of Defense, this mix of forces not only offered the United States a range of
capabilities and flexibility in nuclear planning and complicated an adversary’s attack planning,
but also hedged against unexpected problems in any single delivery system. This latter issue
became more of a concern in this time period, as the United States retired many of the different
types of warheads and missiles that it had deployed over the years, reducing the redundancy in its
force.
The 1991 START Treaty limited the United States to a maximum of 6,000 total warheads, and
4,900 warheads on ballistic missiles, deployed on up to 1,600 strategic offensive delivery
vehicles. However, the treaty did not count the actual number of warheads deployed on each type
of ballistic missile or bomber. Instead, it used “counting rules” to determine how many warheads
would count against the treaty’s limits. For ICBMs and SLBMs, this number usually equaled the
actual number of warheads deployed on the missile. Bombers, however, used a different system.
14 GlobalSecurity.org LGM Minuteman III History and Poseidon C-3 History. http://www.globalsecurity.org/wmd/
systems/lgm-30_3-hist.htm and http://www.globalsecurity.org/wmd/systems/c-3.htm.
15 The older Poseidon submarines were in the process of being retired, and the number of missiles and warheads in the
submarine fleet dropped quickly in the early 1990s, to around 2,688 warheads on 336 missiles by 1993. See Natural
Resources Defense Council. Table of U.S. Strategic Offensive Force Loadings. Archive of Nuclear Data.
http://www.nrdc.org/nuclear/nudb/datab1.asp.
Congressional Research Service
4
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Bombers that were not equipped to carry air-launched cruise missiles (the B-1 and B-2 bombers)
counted as one warhead; bombers equipped to carry air-launched cruise missiles (B-52 bombers)
could carry 20 missiles, but would only count as 10 warheads against the treaty limits. These
rules have led to differing estimates of the numbers of warheads on U.S. strategic nuclear forces
during the 1990s; some estimates count only those warheads that count against the treaty while
others count all the warheads that could be carried by the deployed delivery systems.
According to unclassified data, the United States reduced its nuclear weapons from 9,300
warheads on 1,239 delivery vehicles in 1991 to 6,196 warheads on 1,064 delivery vehicles when
it completed the implementation of START in 2001. By 2009, the United States had reduced its
forces to approximately 2,200 warheads on around 850 delivery vehicles. According to the U.S.
Department of State, as of December 2009, the United States had 1,968 operationally deployed
warheads on its strategic offensive nuclear forces.16 The Bulletin of the Atomic Scientists, in its
Nuclear Notebook, estimated that these numbers held steady in 2010, prior to New START’s
entry into force, then began to decline again, falling to around 1,750 warheads on around 750
delivery vehicles by 2019, as the United States implemented the reductions mandated by New
START (this total includes weapons that the U.S. Department of State does not count in the New
START force).17 These numbers, which have held steady through 2021, appear in Figure 2.
Figure 2. U.S. Strategic Nuclear Forces: 1991-2020
Source: Natural Resources Defense Council, Archive of Nuclear Data, Bulletin of the Atomic Scientists,
Nuclear Notebook.
During the 1990s, the United States continued to add to its Trident fleet, reaching a total of 18
submarines. It retired all of its remaining Poseidon submarines and all of the single-warhead
Minuteman II missiles. It continued to deploy B-2 bombers, reaching a total of 21, and removed
some of the older B-52G bombers from the nuclear fleet. Consequently, in 2001, its warheads
were deployed on 18 Trident submarines with 24 missiles on each submarine and 6 or 8 warheads
on each missile; 500 Minuteman III ICBMs, with up to 3 warheads on each missile; 50
16 U.S. Department of State, Bureau of Verification, Compliance, and Implementation, The Legacy of START and
Related U.S. Policies, Fact Sheet, Washington, DC, July 16, 2009, http://www.state.gov/t/avc/rls/126119.htm.
17 Hans M. Kristensen and Robert S. Norris, “U.S. Nuclear Forces, 2015,” Bulletin of the Atomic Scientists, March
2015. http://bos.sagepub.com/content/71/2/107.full.pdf+html.
Congressional Research Service
5
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Peacekeeper (MX) missiles, with 10 warheads on each missile; 94 B-52H bombers, with up to 20
cruise missiles on each bomber; and 21 B-2 bombers with up to 16 bombs on each aircraft.
The United States and Russia signed a second START Treaty in early 1993. Under this treaty, the
United States would have had to reduce its strategic offensive nuclear weapons to between 3,000
and 3,500 accountable warheads. In 1994, the Department of Defense decided that, to meet this
limit, it would deploy a force of 500 Minuteman III ICBMs with 1 warhead on each missile, 14
Trident submarines with 24 missiles on each submarine and 5 warheads on each missile, 76 B-52
bombers, and 21 B-2 bombers. The Air Force was to eliminate 50 Peacekeeper ICBMs and
reorient the B-1 bombers to nonnuclear missions; the Navy would retire 4 Trident submarines (it
later decided to convert these submarines to carry conventional weapons).
The START II Treaty never entered into force, and Congress prevented the Clinton
Administration from reducing U.S. forces unilaterally to START II limits. Nevertheless, the Navy
and Air Force continued to plan for the forces described above, and eventually implemented those
changes. Table 1 displays the forces the United States had deployed in 2001, after completing the
START I reductions. It also includes those that it would have deployed under START II, in
accordance with the 1994 decisions. (The forces deployed under the 2010 New START Treaty
appear on Table 2, below.)
Table 1. U.S. Strategic Nuclear Forces Under START I and START II
Deployed under START I (2001)
Planned for START II (2003)
Launchers
Accountable
Warheadsa
Launchers
Accountable
Warheads
Minuteman III ICBMs
500
1,200
500
500
Peacekeeper ICBMs
50
500
0
0
Trident I Missiles
168
1,008
0
0
Trident II Missiles
264
2,112
336
1,680
B-52 H Bombers (ALCM)
97
970
76
940
B-52 H Bombers (nonALCM)
47
47
0
0
B-1 Bombersb
90
90
0
0
B-2 Bombers
20
20
21
336
1,237
5,948
933
3,456
System
Total
Source: U.S. Department of State and CRS estimates.
a. Under START I, bombers that are not equipped to carry ALCMs count as one warhead, even if they can
carry up 16 nuclear bombs; bombers that are equipped to carry ALCMs count as 10 warheads, even if they
can carry up to 20 ALCMs.
b. Although they still counted under START I, B-1 bombers are no longer equipped for nuclear missions.
The George W. Bush Administration stated in late 2001 that the United States would reduce its
strategic nuclear forces to 1,700-2,200 “operationally deployed warheads,”18 a goal that was
codified in the 2002 Moscow Treaty. According to the Bush Administration, operationally
18 President Bush announced the U.S. intention to reduce its forces on November 13, 2001, during a summit with
Russia’s President Vladimir Putin. The United States and Russia codified these reductions in a treaty signed in May
2002. See CRS Report RL31448, Nuclear Arms Control: The Strategic Offensive Reductions Treaty, by Amy F. Woolf.
Congressional Research Service
6
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
deployed warheads were those deployed on missiles and stored near bombers on a day-to-day
basis. They are the warheads that would be available immediately, or in a matter of days, to meet
“immediate and unexpected contingencies.”19 The Administration also indicated that the United
States would retain a triad of ICBMs, SLBMs, and heavy bombers for the foreseeable future. It
did not, however, offer a rationale for this traditional “triad,” although the points raised in the past
about the differing and complementary capabilities of the systems probably still pertain. Admiral
James Ellis, the former Commander of the U.S. Strategic Command (STRATCOM), highlighted
this when he noted in a 2005 interview that the ICBM force provides responsiveness, the SLBM
force provides survivability, and bombers provide flexibility and recall capability.20
The Bush Administration did not specify how it would reduce the U.S. arsenal from around 6,000
warheads to the lower level of 2,200 operationally deployed warheads, although it did identify
some force structure changes that would account for part of the reductions. Specifically, after
Congress removed its restrictions,21 the United States eliminated the 50 Peacekeeper ICBMs,
reducing by 500 the total number of operationally deployed ICBM warheads. It also continued
with plans to remove four Trident submarines from service, and converted those ships to carry
nonnuclear guided missiles. These submarines would have counted as 476 warheads under the
START Treaty’s rules. These changes reduced U.S. forces to around 5,000 warheads on 950
delivery vehicles in 2006; this reduction appears above, in Figure 2. The Bush Administration
also noted that two of the Trident submarines remaining in the fleet would be in overhaul at any
given time. The warheads that could be carried on those submarines would not count against the
Moscow Treaty limits because they would not be “operationally deployed.” This would further
reduce the U.S. deployed force by 200 to 400 warheads.
The Bush Administration, through the 2005 Strategic Capabilities Assessment and 2006
Quadrennial Defense Review, announced additional changes in U.S. ICBMs, SLBMs, and
bomber forces; these included the elimination of 50 Minuteman III missiles and several hundred
air-launched cruise missiles. (These are discussed in more detail below.) These changes appeared
to be sufficient to reduce the number of operationally deployed warheads enough to meet the
treaty limit of 2,200 warheads, as the United States announced, in mid-2009, that it had met this
limit. Reaching this level, however, also depends on the number of warheads carried by each of
the remaining Trident and Minuteman missiles.22
Current Force Structure and Size
The Obama Administration indicated in the 2010 NPR that the United States would retain a triad
of ICBMs, SLBMs, and heavy bombers as the United States reduced its forces to the limits in the
2010 New START Treaty. The NPR indicated that the unique characteristics of each leg of the
triad were important to the goal of maintaining strategic stability at reduced numbers of
warheads:
19 U.S. Senate. Committee on Armed Services. Statement of the Honorable Douglas J. Feith, Under Secretary of
Defense For Policy. February 14, 2002.
20 Hebert, Adam. The Future Missile Force. Air Force Magazine. October 2005.
21 Beginning in FY1996, and continuing through the end of the Clinton Administration, Congress had prohibited the
use of any DOD funds for the elimination of strategic nuclear delivery vehicles, below START I levels, until START II
entered into force. See, for example, the FY1998 Defense Authorization Act (P.L. 105-85, §1302). Congress lifted this
restriction in the FY2002 Defense Authorization Act (P.L. 107-107, §1031).
22 “U.S. Meets Moscow Nuclear Reduction Commitment Three Years Early,” Global Security Newswire, February 11,
2009.
Congressional Research Service
7
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Each leg of the Triad has advantages that warrant retaining all three legs at this stage of
reductions. Strategic nuclear submarines (SSBNs) and the SLBMs they carry represent the
most survivable leg of the U.S. nuclear Triad…. Single-warhead ICBMs contribute to
stability, and like SLBMs are not vulnerable to air defenses. Unlike ICBMs and SLBMs,
bombers can be visibly deployed forward, as a signal in crisis to strengthen deterrence of
potential adversaries and assurance of allies and partners. 23
Moreover, the 2010 NPR noted that “retaining sufficient force structure in each leg to allow the
ability to hedge effectively by shifting weight from one Triad leg to another if necessary due to
unexpected technological problems or operational vulnerabilities.”24
The Obama Administration continued to support the triad, even as it reduced U.S. nuclear forces
under New START. In April 2013, Madelyn Creedon, then the Assistant Secretary of Defense for
Global Security Affairs, stated, “The 2010 nuclear posture review concluded that the United
States will maintain a triad of ICBMs, SLBMs, and nuclear capable heavy bombers. And the
president‘s F.Y. ‘14 budget request supports modernization of these nuclear forces.”25 Further, in
its report on the Nuclear Employment Strategy of the United States, released in June 2013, DOD
stated that the United States would maintain a nuclear triad, because this is the best way to
“maintain strategic stability at reasonable cost, while hedging against potential technical problems
or vulnerabilities.”26
Table 2. U.S. Strategic Nuclear Forces under New START
Estimated Forces, 2010
Launchers
Forces Under New START, March 2021a
Warheads
Total
Launchers
Deployed
Launchers
Warheads
Minuteman III
450
500
454
399
399
Trident
336
1,152
280
206
911
B-52
76
300
46
35
36
B-2
18
200
20
11
11
Total
880
2,152
800
651
1,357
Source: U.S. Department of State, Bureau of State, Bureau of Arms Control, Verification, and Compliance, New
START Treaty Aggregate Numbers of Strategic Offensive Forces, Fact Sheet, Washington, DC.
a. The United States retains 14 Trident submarines, with 12 deployed and 2 in overhaul. The submarines in
overhaul do not count against the treaty limits. The Navy has also eliminated 4 launchers on each
submarine, so that each counts as only 20 launchers. The Air Force retains 450 Minuteman III launchers,
although a maximum of 400 hold deployed missiles.
On April 8, 2014, the Obama Administration released a report detailing the force structure that the
United States would likely deploy under New START.27 The report indicated that most of the
reductions would come late in the treaty implementation period so that the plans could change, if
23 Department of Defense, Nuclear Posture Review, Washington, DC, April 6, 2010, p. 22, https://dod.defense.gov/
Portals/1/features/defenseReviews/NPR/2010_Nuclear_Posture_Review_Report.pdf.
24 Ibid., p. 20.
25 U.S. Congress, House Armed Forces, Strategic Forces, Hearing on the Proposed Fiscal 2014 Defense Authorization
as it Relates to Atomic Energy Defense Activities, 113th Cong., 1st sess., May 9, 2013.
26 Department of Defense, Report on Nuclear Employment Strategy of the United States, Washington, DC, June 2013,
p. 5, https://apps.dtic.mil/dtic/tr/fulltext/u2/a590745.pdf.
27 U.S. Department of Defense, Report on Plan to Implement the Nuclear Force Reductions, Limitations, and
Verification, Washington, DC, April 8, 2014.
Congressional Research Service
8
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
necessary. This force structure included 400 Minuteman III missiles, each carrying a single
warhead, and 12 deployed Ohio-class submarines (with 2 in overhaul), with each carrying 20 D-5
Trident II missiles. This force structure was consistent with the statements and adjustments the
Administration had made about deploying all Minuteman III missiles with a single warhead,
retaining Trident submarines deployed in two oceans, and converting some number of heavy
bombers to conventional-only missions. Table 2, above, displays the current U.S. force structure
under New START, and compares it with estimates of U.S. operational strategic nuclear forces in
2010 prior to New START’s entry into force. The current force differs from the force outlined in
2014 because the number of available submarines and missiles can vary day-to-day in response to
maintenance requirements.
The Trump Administration continued to adjust the U.S. nuclear force to meet the New START
limits. When the treaty reductions were completed in February 2018, the U.S. Department of
State reported that the United States had 1,350 warheads on 652 deployed ICBMs, SLBMs, and
heavy bombers, within a total of 800 deployed and nondeployed ICBMs, SLBMs, and heavy
bombers.28 These totals likely exclude one or two Ohio-class submarines that undergoing shortterm maintenance; if these were counted in the active force, the number of deployed launchers
and deployed warheads is likely reach the New START limits of 700 and 1,550, respectively.
The 2018 Nuclear Posture Review reaffirmed the U.S. commitment to the nuclear triad and to the
modernization programs for each of the components of that force structure. It noted that “the
triad’s synergy and overlapping attributes help ensure the enduring survivability of our deterrence
capabilities against attack and our capacity to hold a range of adversary targets at risk throughout
a crisis or conflict. Eliminating any leg of the triad would greatly ease adversary attack planning
and allow an adversary to concentrate resources and attention on defeating the remaining two
legs.”29
The Biden Administration announced, on January 21, 2021, that the United States and Russia
would extend the 2010 New START Treaty by five years, as permitted in the treaty, through
February 5, 2026. The two nations exchanged the necessary documents to complete this extension
on February 3, 2021. The force structure data included in the first data exchange after the
extension appears on Table 2, above. The Biden Administration published the most recent update
to these totals on September 1, 2021, at which time the United States had 1,389 warheads on 665
deployed ICBMs, SLBMs, and heavy bombers, within a total of 800 deployed and nondeployed
ICBMs, SLBMs, and heavy bombers. Although the Biden Administration’s nuclear posture
review has not yet been completed, Secretary of Defense Lloyd Austin and Deputy Secretary of
Defense Kath Hicks both voiced their support for the nuclear triad during their confirmation
hearings in January and February 2021. Moreover, as noted above, the Administration has also
included funding for each of the ongoing nuclear modernization programs in the FY2022 budget
request.
28 U.S. Department of State, Bureau of State, Bureau of Arms Control, Verification, and Compliance, New START
Treaty Aggregate Numbers of Strategic Offensive Forces, Fact Sheet, Washington, DC, https://www.state.gov/t/avc/
newstart/278775.htm.
29 Ibid., p. 43.
Congressional Research Service
9
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Strategic Nuclear Delivery Vehicles: Post-Cold War
Reductions and Current Modernization Programs
Intercontinental Ballistic Missiles (ICBMs)
Peacekeeper (MX)
In the late 1980s, the United States deployed 50 Peacekeeper ICBMs, each with 10 warheads, at
silos that had held Minuteman missiles at F.E. Warren Air Force Base in Wyoming. The 1993
START II Treaty would have banned multiple warhead ICBMs, so the United States would have
had to eliminate these missiles while implementing the treaty. Therefore, the Pentagon began
planning for their elimination, and the Air Force added funds to its budget for this purpose in
1994. However, beginning in FY1998, Congress prohibited the Clinton Administration from
spending any money on the deactivation or retirement of these missiles until START II entered
into force. The Bush Administration requested $14 million in FY2002 to begin the missiles’
retirement; Congress lifted the restriction and authorized the funding. The Air Force began to
deactivate the missiles in October 2002, and completed the process, having removed all the
missiles from their silos, in September 2005. The MK21 reentry vehicles and W87 warheads from
these missiles were placed in storage. As is noted below, the Air Force redeployed some of these
warheads and reentry vehicles on Minuteman III missiles, under the Safety Enhanced Reentry
Vehicle (SERV) program.
Under the terms of the original, 1991 START Treaty, the United States would have had to
eliminate the Peacekeeper missile silos to remove the warheads on the missiles from
accountability under the treaty limits. However, the Air Force retained the silos as it deactivated
the missiles. Therefore, the warheads that were deployed on the Peacekeeper missiles still
counted under START, even though the missiles were no longer operational, until START expired
in December 2009. The United States did not, however, count any of these warheads under the
limits in the Moscow Treaty. The United States has eliminated the empty launchers so that they
do not count under the New START Treaty, although it did not have to blow up or excavate the
silos, as it would have had to do under the original START Treaty. The Air Force filled the silos
with gravel, and completed the elimination process in February 2015.
Minuteman III
The U.S. Minuteman III ICBMs are located at three Air Force bases—F.E. Warren AFB in
Wyoming, Malmstrom AFB in Montana, and Minot AFB in North Dakota. Each base supports
150 missile silos, but only 400 of the 450 silos currently hold operational missiles.
Force Structure Changes
In the 2006 Quadrennial Defense Review (QDR), the Pentagon indicated that it planned to
“reduce the number of deployed Minuteman III ballistic missiles from 500 to 450, beginning in
Fiscal Year 2007.”30 The Air Force deactivated the missiles in Malmstrom’s 564th Missile
Squadron, which was known as the “odd squad.”31 This designation reflected that the launch
control facilities for these missiles used a different communications and launch control system
30 Department of Defense. Report of the 2006 Quadrennial Defense Review. Washington, DC. February 2006. p. 50.
31 Johnson, Peter. Growth Worries Base Boosters. Great Falls Tribune. January 19, 2006.
Congressional Research Service
10
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
than all the other Minuteman missiles. According to Air Force Space Command, the drawdown
began on July 1, 2007. All of the reentry vehicles were removed from the missiles in early 2008,
the missiles were all removed from their silos by the end of July 2008, and the squadron was
deactivated by the end of August 2008.32
In testimony before the Senate Armed Services Committee, General Cartwright, then the
commander of U.S. Strategic Command (STRATCOM), stated that the retired missiles could
serve as test assets for the remaining force, as the Air Force had to “keep a robust test program all
the way through the life of the program.”33 Without these added test assets, the test program could
have started to run short around 2017 or 2018, but the added missiles would likely support the
program through 2025 or longer. When the Air Force retired these missiles, it indicated that it
would not destroy or eliminate the silos. However, with the signing of the New START Treaty in
2010, these silos added to the U.S. total of nondeployed ICBM launchers. Consequently, the Air
Force filled them with gravel in 2014 so that the United States could comply with the New
START limits by 2018.
Some in Congress questioned the Administration’s rationale for the plan to retire 50 Minuteman
missiles, indicating that they believed that more Minuteman silos increased U.S. security and
strengthened deterrence. Congress addressed this again after the United States signed the New
START Treaty, when the Obama Administration considered further reducing the ICBM force
from 450 to 400 deployed missiles. In 2012 and 2013, Congress sought to prevent the Obama
Administration from conducting an environmental assessment needed to advise the elimination of
up to 50 silos. The House Armed Services Committee included a provision in its version of the
FY2015 National Defense Authorization Act (H.R. 4435, §1634) that would require the Air Force
to retain all 450 ICBM silos “in warm status” regardless of future force structure requirements,
budgets, or arms control limits, through 2015.34 Congress has also adopted language that would
preclude further reductions in the numbers of deployed ICBMs. For example, Section 1667 of the
National Defense Authorization Act for FY2017 (P.L. 114-328) stated that none of the FY2017
funds could be obligated or expended for reducing the quantity of deployed intercontinental
ballistic missiles of the United States to a number less than 400.
Congress has included language precluding further reductions in the U.S. ICBM force in every
subsequent NDAA, as some Members continue to debate about the necessity for and numbers of
U.S. land-based missiles. As is noted below, questions about the relationship between deterrence
and the numbers of deployed ICBMs are central to the debate over the new Ground-based
Strategic Deterrent missile.
The Obama Administration announced, in its April 2014 report on its planned force structure
under New START, that the Air Force would to retain 400 deployed Minuteman III ICBMs,
within a total force of 450 deployed and nondeployed launchers. This option has allowed the Air
Force to deactivate missiles in silos that have been damaged by water intrusion, repair those silos,
and return missiles to them at a later date while it repaired additional silos.35 According to the
32 Global Security Newswire. U.S. Deactivates 50 Strategic Missiles. August 4, 2008.
33 U.S. Senate, Committee on Armed Services, Hearing on Global Strike Plans and Programs. Testimony of James E.
Cartwright, Commander U.S. Strategic Command. March 29, 2006.
34 The legislation indicated that “warm status” would enable a “silo to—(1) remain a fully functioning element of the
interconnected and redundant command and control system of the missile field; and (2) be made fully operational with
a deployed missile.”
35 Gabe Starosta, “On New START, Timing Begins to Limit Force-Structure Alternatives,” InsideDefense.com, May
14, 2013.
Congressional Research Service
11
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
data exchanged under the New START Treaty, the Air Force had completed the reductions in
deployed missiles by early June 2017. It now has 400 silos loaded with operational missiles and
50 empty silos that count as “nondeployed” under New START.36
The Air Force has continued to conduct flight tests of the Minuteman III missiles. The live
launches use missiles pulled from operational wings at Minot Air Force Base and Malmstrom Air
Force Base. During these tests, the missiles fly from Vandenberg Air Force Base in California and
deliver a single unarmed warhead to an impact point 4,200 miles (6,759 km) away in the
Kwajalein Atoll in the Pacific Ocean.37 While most occur without incident, the Air Force
terminated a test in late July 2018 due to an unspecified “anomaly.”38 In addition, a test planned
for May 2021 failed after the missile “experienced a ground abort prior to launch.”39
Deployed Warheads
Each Minuteman III missile was initially deployed with 3 warheads, for a total of 1,500 warheads
across the force. In 2001, to meet the START limit of 6,000 warheads, the United States removed
2 warheads from each of the 150 Minuteman missiles at F.E. Warren AFB,40 reducing the
Minuteman III force to 1,200 total warheads. In the process, the Air Force also removed and
destroyed the “bulkhead,” the platform on the reentry vehicle, so that, in accordance with START
rules, these missiles can no longer carry three warheads.
Under START II, the United States would have had to download all the Minuteman III missiles to
one warhead each. Although the Bush Administration initially endorsed the plan to download all
Minuteman ICBMs, this plan apparently changed. In testimony before the Senate Armed Services
Committee in 2006, General Cartwright, who was then the Commander of STRATCOM,
indicated that some Minuteman missiles might carry more than one warhead. Specifically, when
discussing the reduction from 500 to 450 missiles, he said, “this is not a reduction in the number
of warheads deployed. They will just merely be re-distributed on the missiles.”41 Major General
Deppe confirmed that the Air Force would retain some Minuteman III missiles with more than
one warhead when he noted, in a speech in mid-April 2007, that the remaining 450 Minuteman III
missiles could be deployed with one, two, or three warheads.42
In the 2010 NPR, the Obama Administration indicated that, under the New START Treaty, all of
the U.S. Minuteman III missiles would carry only one warhead. It indicated that this
configuration would “enhance the stability of the nuclear balance by reducing incentives for
either side to strike first.”43 The Air Force completed the downloading process, leaving all
36 Captain Esther Willet, 90th Missile Wing Public Affairs, “AF Meets New START Treaty Requirements,” June 28,
2017, http://www.afgsc.af.mil/News/Article-Display/Article/1234307/af-meets-new-start-requirements/.
37 Hans M. Kristensen and Robert S. Norris, “U.S. Nuclear Forces, 2017,” Bulletin of the Atomic Scientists, January
2017, http://www.tandfonline.com/doi/full/10.1080/00963402.2016.1264213.
38
“Unarmed US missile test flight terminated due to anomaly,” Defense News, July 31, 2018.
https://www.defensenews.com/space/2018/07/31/unarmed-us-missile-test-flight-terminated-due-to-anomaly/.
39 Oriana Pawlyk, “Air Force Aborts ICBM Test After Problem on the Ground,” Military Times, May 5, 2021.
https://www.military.com/daily-news/2021/05/05/air-force-aborts-icbm-test-after-problem-ground.html
40 See Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2016. Bulletin of the Atomic Scientists.
January/February 2006.
41 See, U.S. Senate, Committee on Armed Services, Hearing on Global Strike Plans and Programs. Testimony of James
E. Cartwright, Commander U.S. Strategic Command. March 29, 2006.
42 Sirak, Michael. Air Force Prepared To Draw Down Minuteman III Fleet by 50 Missiles. Defense Daily. April 17,
2007.
43 Single-warhead ICBMs are considered to be stabilizing because it would take two attacking warheads to destroy the
Congressional Research Service
12
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Minuteman III missiles with a single warhead, on June 16, 2014.44 The 2018 Nuclear Posture
Review reaffirmed this deployment, with each Minuteman III missile deployed with one warhead
under the New START Treaty.
Unlike under START, the United States did not have to alter the front end of the missile or
remove the old bulkhead. As a result, the United States could restore warheads to its ICBM force
if the international security environment changed. Moreover, this plan could have changed, if, in
an effort to reduce the cost of the ICBM force under New START, the Obama Administration had
decided to reduce the number of Minuteman III missiles further in the coming years. Reports
indicate that the Pentagon may have reviewed such an option as a part of its NPR implementation
study, but, as the report released on April 8, 2014, indicated, it did not decide to pursue this
approach. As a result, under New START, each of the 400 deployed Minuteman III missiles now
carries a single warhead.45
Minuteman Modernization Programs
Over the past 20 years, the Air Force pursued several programs that were designed to improve the
accuracy and reliability of the Minuteman fleet and to “support the operational capability of the
Minuteman ICBM through 2030.” According to some estimates, this effort has cost $6 billion-$7
billion.46 This section describes several of the key programs in this effort.
Propulsion Replacement Program (PRP)
This program, which began in 1998, replaced the propellant, the solid rocket fuel, in the
Minuteman motors to extend the life of the rocket motors. A consortium led by Northrup
Grumman poured the new fuel into the first and second stages and remanufactured the third
stages of the missiles. According to the Air Force, as of early August, 2007, 325 missiles, or 72%
of the fleet, had completed the PRP program; this number increased to around 80% by mid-2008.
The Air Force purchased the final 56 booster sets, for a total of 601, with its funding in FY2008.
Funding in FY2009 supported the assembly of the remaining boosters. The Air Force completed
the PRP program in 2013.47 In the FY2007 Defense Authorization Act (P.L. 109-364) and the
FY2007 Defense Appropriations Act (P.L. 109-289), the 109th Congress indicated that it would
not support efforts to end this program early. However, in its budget request for FY2010, the Air
Force indicated that FY2009 was the last year for funding for the program, as the program was
nearing completion.
Guidance Replacement Program (GRP)
The Guidance Replacement Program extended the service life of the Minuteman missiles’
guidance set, and improved the maintainability and reliability of guidance sets. It replaced aging
silo. If each side has approximately the same number of warheads, than an attack on a single warhead missile would
cost more warheads than it would kill, and, therefore, would not be considered to be lucrative.
44 Jenn Rowell, “Last Malmstron ICBM Reconfigured Under Treaty,” Great Falls Tribune, June 18, 2014.
45 Department of Defense, Nuclear Posture Review, Washington, DC, February 2, 2018, p. 45,
https://media.defense.gov/2018/Feb/02/2001872886/-1/-1/1/2018-NUCLEAR-POSTURE-REVIEW-FINALREPORT.PDF.
46 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
47 Sirak, Michael. Minuteman Fleet has Life Beyond 2020, Says Senior Air Force Space Official. Defense Daily. June
14, 2006.
Congressional Research Service
13
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
parts with more modern and reliable technologies, while maintaining the accuracy of the
missiles.48 Flight testing for the new system began in 1998, and, at the time, it exceeded its
operational requirements. Production began in 2000, and the Air Force purchased 652 of the new
guidance units. Press reports indicate that the system had some problems with accuracy during its
testing program.49 The Air Force eventually identified and corrected the problems in 2002 and
2003. According to the Air Force, 425 Minuteman III missiles were upgraded with the new
guidance packages as of early August 2007. The Air Force had been taking delivery of 5 to 7 new
guidance units each month, for a total of 652 units. Boeing reported that it had delivered the final
guidance set in early February 2009. The Air Force did not request any additional funding for this
program in FY2010. However, it did request $1.2 million in FY2011 and $0.6 million in FY2012
to complete the program. It has not requested additional funding in subsequent years.
Propulsion System Rocket Engine Program (PSRE)
According to the Air Force, the Propulsion System Rocket Engine (PSRE) program was designed
to rebuild and replace Minuteman postboost propulsion system components that were produced in
the 1970s. The Air Force replaced, rather than repaired this system because original replacement
parts, materials, and components were no longer available. This program was designed to reduce
the life-cycle costs of the Minuteman missiles and maintain their reliability through 2020. The Air
Force planned to purchase a total of 574 units for this program. Through FY2009, the Air Force
had purchased 441 units, at a cost of $128 million. It requested an additional $26.2 million to
purchase another 96 units in FY2010 and $21.5 million to purchase 37 units in FY2011. This
completed the purchase of the units. As a result, the budget for FY2012 did not support the
purchase of any additional units, but included $26.1 million for continuing work installing the
units. The FY2013 budget request contained $10.8 million for the same purpose. The Air Force
has not requested additional funding in subsequent years.
Rapid Execution and Combat Targeting (REACT) Service Life Extension Program
The REACT targeting system was first installed in Minuteman launch control centers in the mid1990s. This technology allowed for a significant reduction in the amount of time it would take to
retarget the missiles, automated routine functions to reduce the workload for the crews, and
replaced obsolete equipment.50 In 2006, the Air Force began to deploy a modernized version of
this system to extend its service life and to update the command and control capability of the
launch control centers. This program will allow for more rapid retargeting of ICBMs, a capability
identified in the Nuclear Posture Review as essential to the future nuclear force. The Air Force
completed this effort in late 2006.
Safety Enhanced Reentry Vehicle (SERV)
As was noted above, under the SERV program, the Air Force planned to deploy MK21/W-87
reentry vehicles removed from Peacekeeper ICBMs on the Minuteman missiles, replacing the
older MK12/W62 and MK12A/W78 reentry vehicles. To do this, the Air Force modified the
software, changed the mounting on the missile, and changed the support equipment. According to
Air Force Space Command, the SERV program conducted three flight tests in 2005 and cancelled
48 LGM Minuteman III Modernization. Globalsecurity.org.
49 Donnelly, John M. Air Force Defends Spending Half A Billion on Iffy ICBMs. Defense Week. September 10, 2001.
p. 1.
50 LGM Minuteman III Modernization. Globalsecurity.org.
Congressional Research Service
14
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
a fourth test because the first three were so successful.51 The Air Force installed 20 of the kits for
the new reentry vehicles on the Minuteman missiles at F.E. Warren Air Force Base in 2006. The
process began at Malmstrom in July 2007 and at Minot in July 2008. The Air Force purchased an
additional 111 modification kits in FY2009, for a total of 570 kits. This was the last year that it
planned to request funding for the program. It completed the installation process by 2012.
This program is expected to ensure the reliability and effectiveness of the Minuteman III missiles
throughout their planned deployments. The W-87 warheads entered the U.S. arsenal in 1986 and
were refurbished in 2005. This process extended their service life past 2025.52 As noted below, the
National Nuclear Security Administration (NNSA) has initiated a life extension program for the
W78 warhead, now known as the W87-1, to outfit the new Ground-based Strategic Deterrent
(GBSD) that will replace the Minuteman III missile after 2030.
Solid Rocket Motor Warm Line Program
In the FY2009 Omnibus Appropriations Bill, Congress approved a new program known as the
Solid Rocket Motor Warm Line Program. According to Air Force budget documents, this program
was intended to “sustain and maintain the unique manufacturing and engineering infrastructure
necessary to preserve the Minuteman III solid rocket motor production capability” by providing
funding to maintain a low rate of production of motors each year.53 The program received $42.9
million in FY2010 and produced motors for four Minuteman ICBMs. DOD requested $44.2
million to produce motors for three additional ICBMs in FY2011. The budget request for FY2012
includes an additional $34 million to complete work on the motors purchased in prior years. The
FY2013 budget did not contain any additional funding for this program area, although the Air
Force continues to support the solid rocket motor production base with work funded through its
Dem/Val program (described below).
ICBM Fuze Modernization
According to Air Force budget documents, the ICBM fuze modernization program “is developing
a form, fit and functionally equivalent replacement for the MK21 fuze” and will provide a “30year objective design life.” The Air Force notes that the “legacy Mk21 fuze is three times past its
design life” and it cannot meet the requirements for the nuclear weapons stockpile. The budget
documents also indicate that the MK21 reentry vehicles and the new fuzes will be deployed on
both the current Minuteman III (MM III) and future Ground Based Strategic Deterrent (GBSD)
missile. The budget documents also indicate that this program “will leverage technologies, parts,
components and development/production capabilities resulting from extensive fuze work
performed by the US Navy and NNSA during work on the W88 warhead deployed on Trident II
(D-5) missiles.”
The ICBM fuze modernization program has grown in recent years, from $57.9 million in FY2015
to $142 million in FY2016, $189.8 million in FY2017, $179 million in FY2018, and $172.9
million in FY2019. The Air Force requested, and Congress authorized, $161.2 million for
FY2020 (P.L. 116-92). The Air Force budget documents for FY2020 show that the Air Force
planned to fund the program at $133 million in FY2021, with the program then decreasing to $60
51 Lt. Gen. Frank G. Klotz, Vice Commander, Air Force Space Command. Transcript of Speech to the National
Defense University Breakfast. June 13, 2006.
52 Tom Collina, Fact Sheet: U.S. Nuclear Modernization, Arms Control Association, Washington, DC, January 5, 2009,
http://www.armscontrol.org/USNuclearModernization.
53 http://www.saffm.hq.af.mil/shared/media/document/AFD-100128-067.pdf.
Congressional Research Service
15
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
million in FY2022 and $2 million in FY2023 and FY2024. However, in October 2019, the Air
Force indicated that the program would face delays due to technical issues with the systems
capacitors.54 Consequently, in its budget request for FY2021, the Air Force indicated that the
program required a “rebaseline due to capacitor redesign issues and funding limitations in FY19
and FY20.” It requested $167 million for FY2021 and, following the rebaselining and a
completed design review, the Air Force requested $129.7 million for the ICBM Fuze
Modernization Program in FY2022.
ICBM Dem/Val Program
The Air Force has also funded, through its RDT&E budget, a number of programs under the
ICBM Dem/Val (demonstration and validation) title that are expected to allow it to mature
technologies that might support both the existing Minuteman fleet and the future GBSD program.
Congress appropriated $72.9 million for these programs in FY2014, $30.9 million in FY2015,
$39.8 million in FY2016, and 108.7 million for FY2017.
With the FY2017 budget request, the Air Force moved this program element into the program
element for the GBSD. Hence, although these projects are designed to support both the
Minuteman force and the future GBSD force, they will likely begin to focus more specifically on
the needs of the new missile. In its FY2018 budget request, the Air Force sought only $10.7
million for the Dem/Val program. This represented a significant reduction from the FY2017 level
and from the FY2018 funding anticipated in the FY2017 budget documents. The Air Force noted,
in its FY2018 budget documents, that the FY2018 funding “reflected a realignment of $61.868M
to higher Air Force priorities.” When asked about this realignment, Air Force Vice Chief of Staff
General Stephen Wilson noted that it was not a sign of waning support for the nuclear weapons
modernization programs in the Air Force, but was specific to issues affecting only that program.55
The Air Force requested $41.9 million for this program area in the FY2019 budget; Congress
provided $32.3 million. The Air Force requested $44 million for this program area in FY2020;
Congress provided this amount in the FY2020 National Defense Authorization Act (P.L. 116-92).
The Air Force requested, and Congress authorized, $33 million for this program area in its
FY2021 budget.
The Air Force has requested $49.6 million for the Dem/Val program in its FY2022 budget
request, a reduction from the $55 million anticipated for FY2022 in the FY2021 budget request.
The FY2022 budget documents indicate that this “reflects a $5 million reduction for higher Air
Force priorities.”
The projects funded through the Dem/Val program area include ICBM guidance applications,
ICBM propulsion applications, reentry vehicle applications, and command and control
applications. In the area of guidance applications, DOD is seeking to “identify, develop, analyze,
and evaluate advanced strategic guidance technologies, such as a new solid-state guidance
system, for the ICBM fleet.”56 This new system would increase the accuracy of the ICBM force
and allow the missiles to destroy hardened targets with a single warhead. However, some press
54 This is the same capacitor that, as described below, is likely to cause delays in the W88-Alt and B61-12 warhead life
extension programs. Sara Sirota, “NNSA technical issues cause rebaselining of $2 billion ICBM fuze modernization
program,” Inside Defense, October 24, 2019.
55 Rachal Karas, “Air Force Moving Money From B61, ICBM Upgrades to Fund ‘Higher Priorities,’” Inside Defense,
May 26, 2017.
56 Elaine Grossman, “Key Targeting Tech for Future U.S. Nuclear Missile has Gone Unfunded,” Nextgov.com, August
19, 2014. http://www.thedailybeast.com/articles/2016/02/17/top-secret-u-s-nuke-war-plans-thwarted.html.
Congressional Research Service
16
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
reports questioned whether this program is meeting the needs outlined by the Air Force and
whether it will produce guidance technologies that can provide the needed increases in ICBM
accuracy.57
In the area of propulsion applications, DOD is, among other things, “exploring improvements
and/or alternatives to current propulsion systems.” This program area is specifically seeking to
support the solid rocket motor research and development industrial base, so that it will have the
capacity to support the ICBM force when the Air Force begins the procurement of its new
ground-based strategic deterrent. In the area of reentry vehicle applications, DOD is seeking to
both support reentry systems beyond their original design life and develop and test advanced
technologies to meet future requirements. The area of command and control applications
“evaluates and develops assured, survivable, and secure communications and battlespace
awareness.” It is focusing on both skills and technologies needed to meet current and future
requirements.
Ground-Based Strategic Deterrent (GBSD)
In 2002, the Air Force began to explore its options for a new missile to replace the Minuteman III,
with the intent to begin deploying a new missile in 2018. It reportedly produced a “mission needs
statement” at that time, and then began an Analysis of Alternatives (AOA) in 2004.58 In June
2006, General Frank Klotz indicated that, after completing the AOA, Air Force Space Command
had decided to recommend “an evolutionary approach to the replacement of the Minuteman III
capability,”59 which would continue to modernize the components of the existing missiles rather
than begin from scratch to develop and produce new missiles. He indicated that Space Command
supported this approach because it would be less costly than designing a new system “from
scratch.”
With this plan in place, the Air Force began examining the investments that might be needed to
sustain the Minuteman force through 2030. According to General Robert Kehler, then
Commander-in-Chief of STRATCOM, the missile should be viable throughout that time.60 In
addition, according to DOD officials, flight tests and surveillance programs should provide the
Air Force with “better estimates for component age-out and system end-of-life timelines.”61
At the same time, the Air Force began to consider what a follow-on system to the Minuteman III
might look like for the timeframe after 2030. The Air Force began a capabilities-based assessment
of its land-based deterrent in early 2011 and began a new Analysis of Alternatives (AOA) for the
ICBM force in 2012 with completion expected in mid-2014.62 According to the Air Force, it
requested $2.6 million to begin the study in the FY2012 budget. The FY2013 budget request
57 Elaine M. Grossman, “Top Secret U.S., Nuke War Plans Thwarted,” The Daily Beast, February 17, 2016.
58 Selinger, Mark. Minuteman Replacement Study Expected to Begin Soon. Aerospace Daily and Defense Report. June
25, 2004.
59 Lt. Gen. Frank G. Klotz, Vice Commander, Air Force Space Command. Transcript of Speech to the National
Defense University Breakfast. June 13, 2006.
60 Jason Simpson, “Kehler: Air Force Investigating Minuteman III Follow-On System,” Inside the Air Force, October
8, 2009. See, also, Jason Simpson, “Testers See no Problems With Minuteman III Missiles Lasting to 2030,” Inside the
Air Force, September 4, 2009.
61 See the prepared statement of Assistant Secretary of Defense Madelyn Creedon, U.S. Congress, House Armed
Forces, Strategic Forces, Hearing on the Proposed Fiscal 2014 Defense Authorization as it Relates to Atomic Energy
Defense Activities. 113th Cong., 1st sess., May 9. 2013.
62 Department of Defense, November 2010 Update to the National Defense Authorization Act of FY2010, New START
Treaty Framework and Nuclear Force Structure Plans, Washington, DC, November 17, 2010, p. 11,
http://www.lasg.org/CMRR/Sect1251_update_17Nov2010.pdf.
Congressional Research Service
17
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
included $11.7 million for a new project area known as Ground-based Strategic Deterrence
(GBSD). The FY2014 budget request included $9.4 million to continue this study.
In early January 2013, the Air Force Nuclear Weapons Center issued a “Broad Agency
Announcement (BAA)” seeking white papers for concepts “that address modernization or
replacement of the ground-based leg of the nuclear triad.” The papers produced as a part of this
study served as an early evaluation of alternatives for the future of the ICBM force, and may have
helped select those concepts that would be included in the formal Analysis of Alternatives. The
Air Force Nuclear Weapons Center created five possible paths for further analysis, including one
that would continue to use the current Minuteman III baseline until 2075 without seeking to close
gaps in the missiles’ capabilities, one that would incorporate incremental changes into the current
Minuteman III system to close gaps in capabilities, one that would design a new, fixed ICBM
system to replace the Minuteman III, one that would design a new mobile ICBM system, and one
that would design a new tunnel-based system.
Some analysts expressed surprise at the possibility that the Air Force would consider deploying a
new ICBM on mobile launchers or in tunnels. During the Cold War, the Air Force considered
these types of deployment concepts as a way to increase the survivability of the ICBM force
when faced with the possibility of an attack with hundreds, or thousands, of Soviet warheads.
Even during the Cold War, these concepts proved to be very expensive and impractical, and they
were dropped from consideration after the demise of the Soviet Union and in the face of deep
reductions in the numbers of U.S. and Russian warheads. Some analysts saw the Air Force’s
possible renewed interest in these concepts as a step backward; they argued that the United States
should consider retiring its ICBM force, and should not consider new, expensive schemes to
increase the missiles’ capabilities. Others, however, noted that the presence of these concepts in
the study did not mean that the Air Force would move in this direction. They noted that the 2010
NPR mentioned the possibility of mobile basing for ICBMs as a way to increase warning and
decision time, so it should not be a surprise to see requests for further study. Nevertheless, the
cost and complexity of mobile ICBM basing, again, eliminated these concepts from further
consideration.
According to press reports, the Air Force completed the AOA in 2014. The Air Force had
reportedly decided to pursue a “hybrid” plan that would maintain the basic design of the missile,
the current communications system, and the existing launch silos, but would replace the rocket
motors, guidance sets, postboost vehicles, and reentry systems. However, the Air Force has since
indicated that the GBSD program “will replace the entire flight system, retaining the silo basing
mode while recapitalizing the ground facilities.”
The Air Force received $75 million for the GBSD program in FY2016 and an additional $113
million for FY2017. It requested $215.7 million for FY2018, a reduction from the $294 million
for FY2018 expected in the FY2017 budget documents. The Air Force noted that this reduction of
$78.2 million occurred to align the program with an Independent Cost Estimate conducted by
DOD. Congress authorized $215.7 million for the GBSD in the National Defense Authorization
Act for 2018 (P.L. 115-91). The Defense Authorization Act for 2017 (P.L. 114-328) also included
a provision stating that none funds available in FY2017 or FY2018 could be “obligated or
expended to retain the option for, or develop, a mobile variant of the ground-based strategic
deterrent missile.” The NDAA for 2018 extended this prohibition through FY2019; the NDAA for
FY2019 (P.L. 115-232) extended this prohibition through 2020.
The Air Force requested $345 million for the GBSD program in FY2019. In the National Defense
Authorization Act for Fiscal Year 2019 (P.L. 115-232), Congress added $69.4 million, for a total
authorization of $414.4 million for the GBSD program. The conference report (H.Rept. 115-874)
did not provide a rationale for this increase, although the report from the Senate Armed Services
Congressional Research Service
18
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Committee (S.Rept. 115-262) did note that the program was ahead of schedule and that the
committee “strongly supports the GBSD program as an integral part of the nuclear modernization
effort.” The conference report also required that the Under Secretary of Defense for Acquisition
and Sustainment, in consultation with the Secretary of the Air Force, develop and implement “a
plan to accelerate the development, procurement, and fielding” of the GBSD program. It noted
that the plan should account for the “recapitalization of the full intercontinental ballistic missile
weapon system for 400 deployed missiles and associated spares and 450 launch facilities.”
The Air Force requested $570.3 million of the GBSD program in its budget for FY2020,
consistent with the expected funding level identified in FY2019. Congress approved funding of
$552.4 million in the FY2020 National Defense Authorization Act (P.L. 116-92). The conference
report also included a provision, in Section 1671, mandating that the Secretary of Defense submit
a report to Congress that assesses “the risks and costs resulting from receiving only one bid” for
the engineering and manufacturing development phase of the GBSD program. This provision
responds to concerns about the potential for an increase in the cost of the program after Boeing
withdrew and left Northrop Grumman as the only company competing for the GBSD contract.63
The Air Force requested $1.52 billion for the GBSD program in its FY2021 budget; Congress
authorized $1.5 billion. The Air Force FY2021 budget documents showed that the funding would
continue to increase, growing to $2.5 billion in 2022 and $3 billion per year between 2023 and
2025. According to the Air Force, these increases were “required for FY21 and beyond” to
execute the Engineering & Manufacturing Development phase of the program.
The Air Force requested $2.55 billion for the GBSD program in FY2022. According to the Air
Force budget documents, the significant funding increase for FY2022 is required “to execute the
Engineering & Manufacturing Development (EMD) Contract to advance GBSD major activities.”
Congress has authorized this amount but raised questions about the contracting and oversight
process. In the final version of the FY2022 NDAA (S. 1605, §1650), Congress mandated that the
Secretary of the Air Force, in coordination with the Under Secretary of Defense for Acquisition
and Sustainment, engage with a federally funded research and development center “to conduct a
review of the implementation and the execution of the engineering and manufacturing
development phase for the ground-based strategic deterrent program.” According to this
legislation, the review should consider, among other things, factors associated with the ability of
the Air Force to employ and leverage digital engineering in the GBSD program and options that
may be available to reduce the cost and introduce long-term sustainment efficiencies into the
program.
The final version of the FY2022 NDAA (S. 1605, §1646) also mandates that the Secretary of the
Air Force submit matrices to Congress, along with the annual budget submission for the GBSD,
that identify key milestones, development events, and specific performance goals for the
engineering and manufacturing development phase of the GBSD system along with matrices
related to the expected costs of the system. The Senate Armed Services Committee, in its report
on the 2022 NDAA (S.Rept. 117-39), noted that this type of reporting would “establish the
necessary congressional oversight of this program to ensure it is being executed as described by
the Department of Defense in budget documents to the congressional defense committees.”
63 Valerie Insinna, “Boeing could be out of the Air Force’s competition for next-gen ICBMs for good,” Defense News,
October, 21, 2019, https://www.defensenews.com/smr/nuclear-arsenal/2019/10/22/boeing-could-be-out-of-the-airforces-competition-for-next-gen-icbms-for-good/. See, also, Joe Gould, “House Armed Services chairman takes aim at
Air Force’s handling of ICBM replacement program,” Defense News, October 24, 2019,
https://www.defensenews.com/congress/2019/10/24/hasc-chair-takes-aim-at-air-forces-handling-of-icbm-replacementprogram/?utm_source=Sailthru&utm_medium=email&utm_campaign=EBB%2010.25.19&utm_term=Editorial%20%20Early%20Bird%20Brief.
Congressional Research Service
19
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
The Air Force has indicated that is seeking to deliver “an integrated flight system” beginning in
FY2029, with booster production beginning in FY2026. In FY2017, the Air Force awarded two
contracts—one to Northrop Grumman and one to Boeing—for the Technology Maturation and
Risk Reduction (TMRR) phase of the program, which ran through FY2020. The goals of this
phase were for the contractors to deliver the preliminary design of a “modular, integrated weapon
system” and to “mature technologies related to the major activities and demonstrate performance
of sub-system capabilities through prototyping, modeling, and simulation.” In early September
2020, the Air Force awarded a contract for $13.3 billion to Northrup Grumman to begin the
Engineering and Manufacturing Development phase of the GBSD program.64
According to press reports, the Air Force estimated, in 2015, that the program would cost a total
of $62.3 billion, in then-year dollars, over 30 years. This included $48.5 billion for the acquisition
of 642 missiles, $6.9 billion for command and control systems, and $6.9 billion to renovate the
launch control centers.65 The 642 missiles would support testing and deployment of a force of 400
missiles. Press reports indicate that the Pentagon’s Cost Analysis and Program Evaluation Office
(CAPE) estimated in 2016 that the program would cost $85 billion over that time, with $22.6
billion for research and development, $61.5 billion for procurement, and $718 million for related
military construction.66 The Air Force indicated that the $23 billion difference in estimates was
due to the fact that CAPE used different assumptions and a different methodology in its analysis,
in part, because the United States has not designed and produced long-range missiles in decades.
Normally, DOD would require that the Air Force and CAPE agree on a cost estimate before the
program could proceed, but this was not the case with the GBSD. Deborah Lee James, the
Secretary of the Air Force at the end of the Obama Administration, indicated that it could take a
year or more to refine cost estimates, based on the submissions received by defense industry as
they bid on the program.67 Press reports indicate that, after further analysis, the Air Force and
CAPE assessed in mid-2020 that the GBSD program would cost between $93.1 billion and $95.8
billion. This would support the purchase of 659 missiles, with 25 for initial testing and 634 for
400 missiles in silos, spares, and later testing,68 Press reports indicate that the system could reach
its initial operational capacity, with 9 missiles on alert, by 2029 and would complete the
deployment with 400 missiles on alert in 2036.69
The Air Force also plans to modify and install new command and control systems in all 450
existing launch silos and 45 launch control facilities. Because the Air Force would need to
convert an average of one facility per week, it sought, in its FY2021 budget request, to use
research, development, test and engineering (RDT&E) and missile procurement funding—rather
than military construction funding—to cover the conversion costs. According to the Pentagon,
64 Robert Burns, “Air Force awards $13.3 billion contract for nuclear missiles,” Associated Press, September 8, 2020,
https://www.washingtonpost.com/world/national-security/air-force-awards-133-billion-contract-for-nuclear-missiles/
2020/09/08/e0167fb2-f22a-11ea-8025-5d3489768ac8_story.html.
65 Kingston Reif, “Air Force Drafts Plan for Follow-on ICBM,” Arms Control Today, July/August 2015.
66 Anthony Carpaccio, “America’s New Nuclear Armed Missile Could Cost $85 Billion,” Bloomberg News, September
6, 2016.
67 Aaron Mehta, “Planned ICBM Replacement To Move Forward Without Consensus,” Defense News, September 19,
2016, http://www.defensenews.com/articles/james-new-icbm-cost-question-will-not-impact-next-budget.
68 Anthony Cappacio, “U.S. ICBM to Replace 1970s-Era Minuteman May Cost $111 Billion,” Bloomberg News,
October 1, 2020, https://www.bloomberg.com/news/articles/2020-10-01/pentagon-s-next-generation-icbm-programmay-cost-111-billion.
69 Brian Bradley, “GBSD Scheduled to Reach IOC in FY'29,” Nuclear Security and Deterrence Monitor, August 7,
2015.
Congressional Research Service
20
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
funding this effort through the MilCon budget would require separate budgets and planning, with
each of the separate sites planned as its own military construction case. Pentagon officials
asserted that it could reduce the risk of delays by combining them together into a single program
funded through the RDT&E budget.70 Congress, however, rejected this request in the FY2021
National Defense Authorization Act, requiring, instead, that the funding remain in the Military
Construction budget. Congress did, however, state that the Air Force could request funding with
each missile base identified as a single integrated project.
The GBSD missile will employ an “open architecture” so that technologies can be upgraded as
needed, through the expected 60-year life of the missile. According to officials at Boeing, this
modular, open architecture will help keep down the costs of maintenance and upgrades.71
Moreover, by designing a completely new system, officials believe the Air Force can acquire a
more modern, capable, and flexible system at a lower cost than needed to complete another life
extension of the Minuteman III. The new system would be “flexible for a wide range of
scenarios” and would have improved performance “against modern, precision-guided missile
defenses.”72
Minuteman III Life Extension as an Alternative to GBSD
Several analysts have suggested that the Air Force delay the GBSD program for several years to
reduce the financial pressure on the Pentagon caused by the simultaneous modernization of each
leg of the nuclear triad, the nuclear command and control system, and the major modernization of
conventional forces. According to the Congressional Budget Office, sustaining the existing
nuclear force structure and pursuing the current program of record for modernization could cost
$634 billion between FY2021 and FY2030.73 The Department of Defense, in the 2018 Nuclear
Posture Review, estimated that these costs would total around 6%-7% of the Defense Department
budget through the 2030s,74 although, with the current CBO estimates and expected trajectory of
the Defense budget, that number could rise to 8% or higher. Although a decision to defer the
GBSD program might simply shift costs to later years, some analysts argue that this approach
would relieve pressure on the DOD budget in the near term, leaving more funding for the
acquisition of conventional weapons, readiness, and other DOD priorities.
Some analysts who support a delay in the GBSD program have suggested that the Air Force
combine such a delay with a life-extension program for the Minuteman III missile, thus ensuring
that the United States maintains an effective ICBM force until the GBSD program reaches
completion.75 Those who support this alternative point out that Air Force officials testified in
70 Aaron Mehta, “DoD seeking legislative help for ICBM replacement construction costs,” Defense News, September
25, https://www.defensenews.com/smr/nuclear-arsenal/2020/09/25/dod-seeking-legislative-help-for-icbm-replacementconstruction-costs/.
71
Stew Magnuson, “Air Force on a Long Road to Replace Minuteman III,” National Defense, July 23, 2017.
72 Sydney Freedberg Jr., “New ICBM Cheaper Than Upgraded Minuteman: Boeing on GBSD,” Breaking Defense,
August 2, 2017.
73 Congressional Budget Office, Projected Costs of U.S. Nuclear Forces, 2021-2030, Washington, DC, May 2021, p. 7,
https://www.cbo.gov/system/files/2021-05/57130-Nuclear-Forces.pdf.
74 Department of Defense, Nuclear Posture Review Report, Washington, DC, February 2018,
https://media.defense.gov/2018/Feb/02/2001872886/-1/-1/1/2018-NUCLEAR-POSTURE-REVIEW-FINALREPORT.PDF.
75 George Perkovich and Pranay Vaddi, Proportionate Deterrence: A Model Nuclear Posture Review, Carnegie
Endowment for International Peace, Washington, DC, January 21, 2021, p. 68, https://carnegieendowment.org/files/
Perkovich_Vaddi_NPR_full1.pdf.
Congressional Research Service
21
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
2019 that the missile could be extended one more time.76 Because the Minuteman III fleet is
running short of extra missiles needed for annual tests, those who support this proposal also often
suggest that the Air Force reduce the number of deployed missiles, perhaps from 400 to 300, to
increase the number of missiles available for testing flights prior to the deployment of the GBSD
missile. Moreover, they note that the RAND Corporation, in a study published in 2014, argued
that a life extension of the Minuteman III missile would cost less than the program to acquire the
GBSD missile.77
Some analysts who support a delay in the GBSD program and a life-extension for the Minuteman
III missile argue that this delay would also provide the Air Force with time to reconsider whether
the Air Force could cancel the GBSD program completely, and maintain the U.S. ICBM fleet with
a life-extended Minuteman III missile.78 Some argue that the Air Force studies showing that the
Minuteman III life extension would be more expensive than the GBSD were flawed because they
began with the assumption that the United States will need a force of 400 missiles through 2075.
Thus, they contend the studies not only ignored possible improvements in the threat environment
and reduced requirements for ICBMs, but also assumed that the United States would eventually
need the GBSD program even if it life-extended the Minuteman III missile. Consequently, some
have argued that Congress should mandate a new independent study that included alternative
assumptions about future threats and requirements and alternative force options to meet the
requirements for land-based missiles.79
In recent testimony, General Tim Ray, the Commander of Air Force Global Strike Command, and
Admiral Charles Richard, the Commander of U.S. Strategic Command (STRATCOM), disputed
these arguments. General Ray noted that the Air Force conducted two studies that compared the
costs of the GBSD program and a Minuteman III life-extension program, and concluded that the
life-extension program would cost $38 billion more than the GBSD program. He also argued that
the GBSD program would be more cost-effective than the life-extension program because it
would provide the Air Force with a modern missile with greater capabilities and lower
maintenance and sustainment costs.80 Admiral Richard argued, in testimony before the House and
Senate Armed Services Committees, that a Minuteman III life-extension program would not even
be possible because the Air Force lacks necessary parts and technologies for a life-extended
missile. He also argued that a life-extended Minuteman missile would not have the capacity to
76 Union of Concerned Scientists, Rethinking Land-Based, Washington, DC, January 2020, p. 18,
https://www.ucsusa.org/sites/default/files/2020-06/rethinking-land-based-nuclear-missiles.pdf. See also comments by
Representative John Garamendi, in U.S. Congress, House Committee on Armed Services, Subcommittee on Strategic
Forces, FY2022 National Defense Authorization Request for Strategic Forces, Hearing, 117 th Cong., 1st sess., April 21,
2021.
77 Lauren Caston, Robert S. Leonard, Christopher A. Mouton, Chad J. R. Ohlandt, Craig Moore, Raymond E. Conley,
and Glenn Buchan, The Future of the US Intercontinental Ballistic Missile Force, Santa Monica, CA: RAND
Corporation, 2014.
78 Daryl Kimball, “Enough Already: No New ICBMs,” Arms Control Today, March 2021,
https://www.armscontrol.org/act/2021-03/focus/enough-already-no-new-icbms.
79 Ankit Panda, “We Don’t Have Enough Information to Evaluate Arguments for a New ICBM,” Defense One, May 3,
2021, https://www.defenseone.com/ideas/2021/05/we-dont-have-enough-information-evaluate-arguments-new-icbm/
173775/.
80 Captain Christina Camp, Global Strike Command commander addresses Congressional committee, Air Force Global
Strike Command Public Affairs, Barksdale, LA, May 14, 2021, https://www.afgsc.af.mil/News/Article-Display/Article/
2618198/global-strike-command-commander-addresses-congressional-committee/.
Congressional Research Service
22
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
meet the ICBM requirements into the future, noting that “you cannot indefinitely life-extend
anything and I cannot deter with the leftovers of the Cold War forever.”81
W87-1 Warhead
The Air Force plans to replace the W78 warhead currently carried by the Minuteman III missile
with a new warhead when it deploys the new GBSD missile. The W87-1 warhead is the third and
current iteration of this new warhead.
The W78 warhead is the oldest warhead in the U.S. stockpile, dating from 1979. The Obama
Administration outlined a plan to replace it with a new warhead, known as the IW1 (Interoperable
Warhead-1), which could have been delivered by ICBMs (in place of the W78 warhead) and
SLBMs (in place of the W88 warheads). The Obama Administration suspended work on this new
warhead in FY2016 and did not request any funding for it in the FY2017 and FY2018 budget
requests. In the FY2019 budget request for the National Nuclear Security Administration
(NNSA), the Trump Administration requested $53 million to resume research and development
activities on the IW1. Congress enacted this amount, but requested a study on the rationale for
and alternatives to the plan to use an interoperable warhead as a part of the W78 life extension
program.
During 2018, NNSA dropped the IW1 designator and, instead, pursued a life extension program
for just the W78 ICBM warhead. It then designated this program as the W87-1, to reflect the fact
that it has a similar primary design to the existing W87 warhead, a warhead also carried by the
Minuteman III ICBM. According to a report provided to Congress in late 2018, [NNSA] “is no
longer planning for an interoperable warhead program as previously conceived,” and no longer
plans to “pursue a W78 life-extension program using the existing aeroshell.”82 Instead, the new
warhead, like the existing W87 warhead, the warhead will use insensitive high explosives (IHE)
that meet Air Force and NNSA safety and security requirements. NNSA expects that the new
warhead will cost between $8.6 billion and $14.8 billion, before accounting for the new
plutonium pit inside the warhead.
According to the report provided to Congress, “NNSA is currently planning for the W87-1
program to include newly manufactured pits.”83 NNSA currently has only a limited capacity to
produce new plutonium pits, with that capacity located at Los Alamos National Laboratory in
New Mexico. In May 2018, NNSA announced that would pursue a new approach for plutonium
pit production to meet the requirement of producing a minimum of 80 pits per year by 2030, as
outlined in the 2018 Nuclear Posture Review. Instead of focusing solely on building capacity at
Los Alamos National Laboratory, NNSA decided to “repurpose the Mixed Oxide (MOX) Fuel
Fabrication Facility at the Savannah River Site to produce at least 50 pits per year” and to
continue work that would allow Los Alamos to produce “no fewer than 30 pits per year.”84 Critics
81 Jacqueline Feldscher, “U.S. urgently needs new nukes to counter Russia, China, admiral says,” Politico, April 20,
2021. See, also, statement of Admiral Charles Richard, in U.S. Congress, House Committee on Armed Services,
Subcommittee on Strategic Forces, FY2022 National Defense Authorization Request for Strategic Forces, Hearing,
117th Cong., 1st sess., April 21, 2021.
82 Department of Energy, National Nuclear Security Administration, W78 Replacement Program (W87-1): Cost
Estimates and Use of Insensitive High Explosives, Washington, DC, December 8, 2018, p. 2,
http://www.airforcemag.com/Features/Documents/
W78%20Replacement%20Program%20Cost%20Estimates%20IHE.pdf.
83 Ibid. p. 5.
84U.S. Department of Energy, National Nuclear Security Administration, Plutonium Pit Production, Fact Sheet,
Washington, DC, April 2019, https://www.energy.gov/sites/prod/files/2019/05/f62/2019-05-13-FACTSHEET-
Congressional Research Service
23
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
have questioned whether NNSA will be able to meet this schedule, and even those who support
the effort note that it will be a challenge.85 Moreover, NNSA has recently indicated that the
schedule for the Savannah River Site will likely slip, with the goal of producing 50 pits per year
moving from 2030 to 2032-2035.
NNSA has apparently recognized the possibility that it will not have enough new pits available to
support the GBSD deployment schedule with W87-1 warheads. In its budget documents, NNSA
has indicated that it plans to complete the first production unit of the W87-1 in FY2030.
However, the FY2021 budget documents also note that the W87-0 warhead, which is currently
deployed on U.S. ICBMs, will also be “qualified and deployed onto the GBSD.” During recent
testimony, Dr. Charles Verdon, the acting Administrator of NNSA, confirmed that nearly half the
W87-0 warheads on Minuteman III missiles will transition to the GBSD.86 Thus, the W87-0
warhead would provide the Air Force with an alternative warhead if the W87-1 warhead is
delayed.
NNSA requested $112 million in FY2020 for the W87-1 warhead modification program. NNSA
also requested $420 million in FY2020 to support design activities at Savannah River and begin
the modifications needed to produce 50 pits per year at the repurposed facility by 2030. In
addition, the Air Force requested $75.6 million for the MK21A Reentry Vehicle Program in
FY2020. This program will “design, develop, produce, and deploy an integrated reentry vehicle
capable of delivering the W87-1 warhead.”
The House, in its version of the FY2020 National Defense Authorization Bill (H.R. 2500),
reduced the request for the W87-1 warhead to $53 million and the request for to support design
activities at Savannah River to $179 million. The Senate’s version of the bill supported the budget
requests, and the Congress approved $112 million for the W87-1 modification program and $65.7
million for the MK21A Reentry Vehicle Program in the Conference Report on the FY2020
National Defense Authorization Act (P.L. 116-92). Congress also appropriated $420 million to
support design activities at Savannah River.
NNSA requested $541 million W87-1 warhead modification program in FY2021. Congress
authorized this funding in the FY2021 National Defense Authorization Act. NNSA has indicated
that this increase over the $112 million enacted for the W87-1 in FY2020 reflects a “ramp-up” of
activities across all program areas. NNSA also requested $441.9 million to support the design of
the new pit facility and plutonium processing at Savannah River. Congress also authorized this
funding in the FY2021 National Defense Authorization Act. The Air Force also requested, and
Congress authorized, $112.8 million for the MK21A Reentry Vehicle Program in FY2021.
NNSA has requested $691 million for the W87-1 warhead modification program in FY2022. The
increases in funding for the W87-1 in FY2021 and FY2022 reflect a “ramp-up” of activities
across all program areas. NNSA has also requested $603 million for plutonium operations and the
design of the new pit production facility at Savannah River. Congress authorized these funding
requests in the FY2022 NDAA but also mandated (S. 1605, §3111) that NNSA report to Congress
on the planned production goals of both the Savannah River and Los Alamos National Laboratory
plutonium-pits.pdf.
85 Dan Leone, “NNSA Downplays Study that Says Agency Can’t Make 50 Nuke Cores Per Year by 2030 in S.C.,”
Nuclear Security and Deterrence Monitor, April 12, 2019. See, also, Colin Demarest, The Aiken Standard, August 28,
2019, https://www.aikenstandard.com/news/going-gangbusters-srns-chief-says-plutonium-work-harkens-back-to/
article_a94e8d8a-c995-11e9-8741-2f606f64ed72.html.
86 U.S. Congress, Senate Committee on Armed Services, Department of Energy and National Nuclear Security
Administration on Atomic Energy Defense Activities, Hearing, 117th Cong., 1st sess., June 24, 2021, p. 46,
https://www.armed-services.senate.gov/imo/media/doc/21-58_06-24-2021.pdf.
Congressional Research Service
24
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
pit production projects during the first 10 years of their operations. According to the legislation,
this report should describe, among other things, the number of war reserve plutonium pits planned
to be produced during each year and “an explanation of any changes to the production goals or
requirements as compared to the report submitted during the previous year.”
Submarine-Launched Ballistic Missiles
The U.S. fleet of ballistic missile submarines consists of 14 Trident (Ohio-class) submarines, each
originally equipped to carry 24 Trident missiles. With 2 submarines in overhaul, the operational
fleet of 12 submarines currently carries around 1,100 warheads. To comply with the launcher
limits in New START, each of the submarines can now carry only 20 missiles. The four empty
launch tubes have been removed from accountability under New START after being modified so
that they cannot carry or launch missiles. As a result, the 14 submarines count as a total of 280
deployed and nondeployed launchers, with 240 deployed launchers counting on the 12
operational submarines.
By the early 1990s, the United States had completed the deployment of 18 Trident ballistic
missile submarines (SSBNs). Each of these submarines was equipped to carry 24 Trident
missiles, and each missile could carry up to 8 warheads (either W-76 warheads or the larger W-88
warheads on the Trident II missile). The Navy initially deployed eight of these submarines at
Bangor, WA, and all eight were equipped with the older Trident I missile. It then deployed 10
submarines, all equipped with the Trident II missile, at Kings Bay, GA. During the 1994 Nuclear
Posture Review, the Clinton Administration decided that the United States would reduce the size
of its Trident fleet to 14 submarines, and that 4 of the older submarines would be “backfit” to
carry the Trident II missile.
The Bush Administration’s 2001 Nuclear Posture Review endorsed the plan to backfit four of the
Trident submarines so that all would carry Trident II missiles. It also indicated that, instead of
retiring the remaining four submarines, the Navy would convert them to carry conventional
weapons, and designated them “guided missile” submarines (SSGNs). The 2010 NPR also
endorsed a force of 14 Trident submarines, although it noted that it might reduce that force to 12
submarines in the latter half of this decade. As was noted above, each submarine will deploy with
only 20 missiles to meet the reductions in New START. As a result, the U.S. ballistic missile
submarine (SSBN) force may continue to consist of 14 Trident submarines, with 2 in overhaul,
through New START implementation.
The SSGN Program
The Navy converted four Trident submarines (the USS Ohio, USS Michigan, USS Florida, and
USS Georgia) to carry conventional cruise missiles and other conventional weapons. Reports
indicate that the conversion process took approximately $1 billion and two years for each of the
four submarines. The SSGNs can each carry 154 Tomahawk cruise missiles, along with up to 100
special forces troops and their mini-submarines.87
The first two submarines scheduled for this conversion were removed from the nuclear fleet in
early 2003. They were slated to receive their engineering overhaul, then to begin the conversion
process in 2004.88 The first to complete the process, the USS Ohio returned to service as an
87 Connolly, Allison. For Four Subs, Its Good-bye Ballistic Missiles, Hello SEALs. Norfolk Virginia Pilot. December
18, 2004.
88 Ohio Class SSGN Tactical Trident. GlobalSecurity.org http://www.globalsecurity.org/military/systems/ship/ssgn-
Congressional Research Service
25
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
SSGN in January 200689 and achieved operational status on November 1, 2007. According to the
Navy, the Georgia was scheduled for deployment in March 2008, and the other submarines were
scheduled to reach that status later in the year.90 According to Admiral Stephen Johnson, the
Director of the Navy’s Strategic Submarine Program (SSP), all four of the submarines had
returned to service by mid-2008, and two were forward-deployed on routine patrols. According to
the Navy, these submarines are likely to remain in service through the mid-2020s.
The Backfit Program
As was noted above, both the 1994 and 2001 Nuclear Posture Reviews confirmed that the Navy
would backfit four Trident submarines so that they could carry the newer Trident II (D-5) missile.
This process not only allowed the Navy to replace the aging C-4 missiles, it also equipped the
fleet with a missile that has improved accuracy and a larger payload. With its greater range, it
would allow the submarines to operate in a larger area and cover a greater range of targets. These
characteristics were valued when the system was designed and the United States sought to
enhance its ability to deter the Soviet Union. The Bush Administration believed that the range,
payload, and flexibility of the Trident submarines and D-5 missiles remained relevant in an era
when the United States may seek to deter or defeat a wider range of adversaries. The Obama
Administration has emphasized that, by providing the United States with a secure second strike
capability, these submarines enhance strategic stability.
Four of the eight Trident submarines based in Bangor, WA (USS Alaska, USS Nevada, USS
Henry M. Jackson, and USS Alabama) were a part of the backfit program. During the process, the
submarines underwent a preplanned engineered refueling overhaul, which accomplishes a number
of maintenance objectives, including refueling of the reactor, repairing and upgrading some
equipment, replacing obsolete equipment, repairing or upgrading the ballistic missile systems,
and other minor alterations.91 The submarines also are fit with the Trident II missiles and the
operating systems that are unique to these missiles. The Henry M. Jackson and Alabama were
completed their engineering overhaul and backfit in FY2006 and reentered the fleet in 2007 and
2008. The last of the Trident I (C-4) missiles was removed from the fleet in October 2004, when
the USS Alabama off-loaded its missiles and began the overhaul and backfit process. All the
Trident submarines currently in the U.S. fleet now carry the Trident II missile.92
Basing Changes
When the Navy first decided, in the mid-1990s, to maintain a Trident fleet with 14 submarines, it
planned to “balance” the fleet by deploying 7 Trident submarines at each of the 2 Trident bases.
The Navy would have transferred three submarines from Kings Bay to Bangor, after four of the
submarines from Bangor were removed from the ballistic missile fleet, for a balance of seven
submarines at each base. However, these plans changed after the Bush Administration’s Nuclear
726.htm.
89 First Trident Submarine Converted. Associated Press. January 10, 2006.
90 U.S. Congress. Senate. Armed Services Committee, Subcommittee on Strategic Forces. Fiscal Year 2008 Strategic
Forces Program Budget. Hearing. Prepared statement of Mr. Brian R. Green, Deputy Assistant Secretary of Defense,
Strategic Capabilities, p. 6. March 28, 2007. See also, Guided Missile Submarine Ohio Ready for Deployment. Inside
the Navy, November 5, 2007.
91 SSBN-726 Ohio-Class FBM Submarines, GlobalSecurity.org, http://www.globalsecurity.org/wmd/systems/ssbn-726recent.htm.
92 Morris, Jefferson. Older Trident Missiles to be Phased out by Fall, Admiral Says. Aerospace Daily and Defense
Report, June 17, 2005.
Congressional Research Service
26
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Posture Review. The Navy has transferred five submarines to Bangor, “balancing” the fleet by
basing nine submarines at Bangor and five submarines at Kings Bay. Because two submarines
would be in overhaul at any given time, this basing plan means that seven submarines would be
operational at Bangor and five would be operational at Kings Bay.
According to unclassified reports, the Navy began moving Trident submarines from Kings Bay to
Bangor in 2002, and transferred the fifth submarine in September 2005.93 This change in basing
pattern apparently reflected changes in the international security environment, with fewer targets
within range of submarines operating in the Atlantic, and a greater number of targets within range
of submarines operating in the Pacific. In particular, the shift allows the United States to improve
its coverage of targets in China and North Korea.94 Further, as the United States modifies its
nuclear targeting objectives it could alter the patrol routes for the submarines operating in both
oceans, so that a greater number of emerging targets would be within range of the submarines in a
short amount of time.
Warhead Loadings
The Trident II (D-5) missiles can be equipped to carry up to eight warheads each. Under the terms
of the original START Treaty, which was in force from 1994 to 2009, the United States could
remove warheads from Trident missiles, and reduce the number listed in the database, a process
known as downloading, to comply with the treaty’s limit of 6,000 warheads. The United States
took advantage of this provision, reducing to six warheads per missile on the eight Trident
submarines based at Bangor, WA.95 During the George W. Bush Administration, the Navy further
reduced the number of warheads on the submarines so that the United States could reduce its
forces to the 2,200 deployed warheads permitted under the 2002 Moscow Treaty. The United
States did not have to reach this limit until 2012, but it had done so by 2009.
The United States has continued to reduce the total numbers of warheads carried on its Trident
missiles to reach the New START Treaty limits. Unlike START, which attributed the same
number of warheads to each missile of a given type, regardless of whether some of the missiles
carried fewer warheads, the United States can deploy different numbers of warheads on different
missiles, and count only the actual warheads deployed on the force. This allows each missile to be
tailored to meet the mission assigned to that missile.96 The United States does not need to indicate
how many warheads are deployed on each missile at all times; it must simply report the total
number of operationally deployed warheads on all of its strategic nuclear delivery vehicles. The
United States and Russia can confirm that actual number of warheads on a specific missile, with
random, short-notice inspections. Moreover, the United States will not have to alter the platforms
in the missiles, so it could restore warheads to its Trident missiles if circumstances changed.
93 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
94 Ibid.
95 Even though four of these submarines are being converted to SSGNs, they still count under the START Treaty
because they still have SLBM launch tubes. Each of those tubes count as six warheads. See U.S. Department of State.
Bureau of Verification, Compliance, and Implementation. START Aggregate Number of Strategic Offensive Arms.
April 1, 2006.
96 Hans M. Kristensen and Robert S. Norris, “United States Nuclear Forces, 2017,” Bulletin of the Atomic Scientists,
December 2016, p. 52.
Congressional Research Service
27
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Modernization Plans and Programs
The Navy initially planned to keep Trident submarines in service for 30 years, but then extended
that time period to 42 years. This extension reflects the judgment that ballistic missile submarines
would have operated with less demanding missions than attack submarines, and could, therefore,
be expected to have a much longer operating life than the expected 30-year life of attack
submarines. Therefore, since 1998, the Navy has assumed that each Trident submarine would
have an expected operating lifetime of at least 42 years, with two 20-year operating cycles
separated by a 2-year refueling overhaul.97 With this schedule, the submarines will begin to retire
from the fleet in the late 2020s. The Navy has also pursued a number of programs to ensure that it
has enough missiles to support this extended life for the submarines.
Trident Missile Production and Life Extension
The Navy purchased a total force of 533 D-5 missiles through 2012. It continued to produce
rocket motors, at a rate of around one per month, and to procure alternation kits (known as
SPALTs) needed to meet the extended service life of the submarine. Although the Navy plans to
deploy its submarines with only 240 ballistic missiles under New START, it needs the greater
number of missiles to support the fleet throughout the their life-cycle. In addition, around 50 of
the Trident missiles are available for use by Great Britain in its Trident submarines. The
remainder would support the missile’s test program throughout the life of the Trident system.
The Navy is pursuing a life extension program for the D-5 missiles, known as the D5LE (D-5
Life Extension) so that they will remain capable and reliable throughout the 42-year life of the
Trident submarines; they will also serve as the initial missile on the new Columbia class
submarine, supporting that system through 2039. The funding for the Trident II missile supported
the purchase of additional solid rocket motors other critical components required to support the
missile throughout its service life. Reports indicate the Navy started loading the submarines with
the new missile in 2017.98
In 2019, the Navy’s Strategic Systems Program office indicated that it would begin a second life
extension program for the Trident II missile—known as the D5LE2—to replace old parts and
ensure the missiles’ reliability through the life of the Columbia class submarine.99 Reports
indicate that the Navy planned to spend $700 million over six years to conduct studies and
analyses, with the design of the new missile beginning in FY2025.100
According to the Navy’s budget documents for FY2022, the D5LE missile would not be able to
support the Columbia class submarine “beginning in 2039 through its predicted service life
(2084) due to age, attrition, and obsolescence of critical components.” The D5LE2 will, therefore,
“address the Columbia service life requirement ... to ensure a credible and survivable strategic
deterrent through the service life of COLUMBIA Class SSBNs.” Vice Admiral Johnny Wolfe, the
director, Strategic Systems Programs (SSP), noted, during testimony before the House Armed
97 SSBN Ohio-Class FBM Submarines. GlobalSecurity.org.
98 Hans M. Kristensen and Robert S. Norris, “U.S. Nuclear Forces, 2018,” Bulletin of the Atomic Scientists, March
2018, https://www.tandfonline.com/doi/pdf/10.1080/00963402.2018.1438219?needAccess=true.
99 Megan Eckstein, “Navy Beginning Tech Study to Extend Trident Nuclear Missile Into the 2080s,” USNI News,
November 14, 2019, https://news.usni.org/2019/11/14/navy-beginning-tech-study-to-extend-trident-nuclear-missileinto-the-2080s.
100 Jason Sherman, “Navy reveals six-year, $700M plan to design second Trident SLBM life extension,” Inside
Defense, March 6, 2020, https://insidedefense.com/daily-news/navy-reveals-six-year-700m-plan-design-second-tridentslbm-life-extension.
Congressional Research Service
28
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Services Committee in June 2021, that the D5LE2 “will yield multiple benefits in missile
performance.” He further indicated that the changes could be “so extensive” that the missile will
essentially be a new weapon. He argued that it was needed to “ensure that Trident remains
credible in the face of a dynamic threat environment.” 101
The Navy allocated $5.5 billion to the Trident II missile program in FY2008 and FY2009. This
funding supported the purchase of an additional 36 Trident II missiles. The Navy spent $1.05
billion on Trident II modifications in FY2010 and requested $1.1 billion in FY2011. In FY2010,
$294 million was allocated to the purchase of 24 new missiles, $154.4 million was allocated to
missile support costs, and $597.7 million was allocated to the Trident II Life Extension program.
In FY2011, the Navy requested $294.9 million for the purchase of 24 new missiles, $156.9
million to missile support costs, and $655.4 million to the Trident II Life Extension Program. The
FY2012 budget included $1.3 billion for Trident II missile program. Within this total, $191
million was allocated to the purchase of 24 additional new missiles, $137.8 million was allocated
to missile support costs, and $980 million was allocated to the Trident II Life Extension Program.
This was the last year during which the Navy sought to purchase new Trident II missiles. The
FY2013 budget requested $1.2 billion for the Trident II missile program. This total included $524
million for program production and support costs, and $700.5 million for the Trident II life
extension program. The Navy requested $1.14 billion for this program area in FY2014. According
to the Navy’s budget documents, this allowed it to continue to purchase components, such as the
alteration kits for the guidance and missile electronics systems and solid rocket motors for these
missiles. The Navy received $1.17 billion for FY2015 and $1.1 billion for FY2016 for Trident II
modifications.
The Navy requested, and Congress authorized, $1.1 billion for Trident II modifications in
FY2017, $1.2 billion in FY2018, and $1.1 billion in FY2019. In its FY2020 budget request, the
Navy requested $1.17 billion for Trident II modifications, with the funding covered through the
Overseas Contingency Operations (OCO) portion of the Pentagon budget. When asked about this
anomaly, the Navy confirmed that it did not plan to employ Trident missiles in ongoing overseas
operations, and that it was instructed to fund the program through OCO to meet the constraints of
the Budget Control Act. Congress approved this funding in the FY2020 National Defense
Authorization Act (P.L. 116-92). The Navy plans to spend about $5 billion on Trident II
modifications between FY2021 and FY2024.
The Navy requested $1.17 billion for Trident II modifications in FY2021. Within this total, the
Navy requested $111 million for the D5LE2 project. Although not noted in the budget
document’s description, $32 million will support the development of the MK7 aeroshell, which
will be deployed on the D5LE2 missile with the new W93 warhead (described below). Congress
approved these amounts in the FY2021 National Defense Authorization Act.
The Navy has requested $1.14 billion for Trident II modifications in FY2022. Congress
authorized this funding in the FY2022 NDAA.
W76 Warhead Life Extension
The overwhelming majority of Trident missiles are deployed with the MK4/W76 warhead, which,
according to unclassified estimates, has a yield of 100 kilotons.102 It is recently completed a life
101 Richard R. Burgess, “Navy’s SSP Admiral: New Missile Planned for Introduction on 9 th Columbia SSBN,”
Seapower Magazine, June 10, 2021, https://seapowermagazine.org/navys-ssp-admiral-new-missile-planned-forintroduction-on-9th-columbia-ssbn/.
102 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2015. Bulletin of the Atomic Scientists. March
2015, http://bos.sagepub.com/content/71/2/107.full.pdf+html.
Congressional Research Service
29
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
extension program (LEP) that was designed to enhance its capabilities. According to some
reports, the Navy had initially planned to apply this program to around 25% of the W76
warheads, but then increased that plan to cover more than 60% of the stockpile. NNSA completed
production of the W76-1 LEP in 2019. The LEP is intended to add 30 years to the warhead life
“by refurbishing the nuclear explosive package, the arming, firing, and fusing system, the gas
transfer system, and associated cables, elastomers, valves, pads, cushions, foam supports,
telemetries, and other miscellaneous parts.”
NNSA requested $224.1 million for the W76 LEP in FY2018 and $133.9 million in FY2019. It
did not request any additional funding in FY2020 or FY2021 due to the “completion of remaining
W76 warhead modifications and associated deliveries to the Navy. The FY2019 budget
documents also introduced a new component to the W76 LEP. NNSA noted that “the 2018
Nuclear Posture Review (NPR) states that the United States will modify a small quantity of
existing SLBM warheads to provide a low-yield option in the near-term.” The NPR views this
capability as a response to the belief that Russia, using what is often referred to as the “escalate to
de-escalate” doctrine, might misjudge U.S. willingness to respond to the limited first use of
nuclear weapons during a conventional conflict in Europe. The NPR argues that, by deploying a
low-yield SLBM warhead, the United States will “ensure that the Russian leadership does not
miscalculate regarding the consequences of limited nuclear first use” and will “understand that
nuclear first-use, however limited, will fail to achieve its objectives, fundamentally alter the
nature of a conflict, and trigger incalculable and intolerable costs for Moscow.”103
NNSA designated the low-yield version of the W76 warhead as the W76-2. NNSA’s FY2019
budget request did not request any funding specifically allocated to this modification, but it did
note that “as the Nuclear Weapons Council translates policy into military requirements, the
Administration will work with Congress for appropriate authorizations and appropriations to
develop options that support the modification.” The White House later included a request for $65
million for this modification in a budget amendment package submitted to Congress on April 13,
2018. This document stated that the amendment would “authorize the production of low-yield
ballistic missiles to replace higher-yield weapons currently deployed, maintaining the overall
number of deployed U.S. ballistic missile warheads.” It noted that a delay in the program past
FY2019 “would require a restart of the W76 production line, increase costs, and delay delivery to
the Department of Defense.”104
Congress approved the FY2019 funding request in the Energy and Water Appropriations Act,
H.R. 5895, and noted, in the conference report (H.Rept. 115-929), that NNSA must “comply with
the direction in the House report regarding the W76-2.” The House report (H.Rept. 115-697)
mandated that NNSA provide Congress with “a report detailing the plan, rationale, costs, and
implications of producing a low-yield variant of the W76 warhead.” The report is to include not
only cost and schedule estimates, but also a “detailed discussion of the military requirements
associated with the W76-2.”
NNSA completed its work on the W76-2 warhead in FY2019, so it requested only $10 million for
the program in FY2020 to support program documentation and close out activities. The Navy also
requested $19.6 million to begin the integration of the warhead onto its D-5 missiles. The House,
in its version of the FY2020 National Defense Authorization Act [H.R. 2500] prohibited the use
103 Department of Defense, Nuclear Posture Review, Washington, DC, February 2, 2018, p. 30,
https://media.defense.gov/2018/Feb/02/2001872886/-1/-1/1/2018-NUCLEAR-POSTURE-REVIEW-FINALREPORT.PDF.
104 Aaron Mehta, “Trump administration repurposes $65 million for new nuclear warhead design,” Defense News, April
17, 2018, https://www.defensenews.com/smr/nuclear-triad/2018/04/17/trump-administration-repurposes-65-millionfor-new-nuclear-warhead-design/.
Congressional Research Service
30
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
of FY2020 funds for that purpose. The Senate version of the bill included the funding, and
Congress approved the requests for both $10 million for NNSA and $19.6 million for the Navy in
the final version of the FY2020 National Defense Authorization Act (P.L. 116-92).
Press reports indicate that the Navy began to deploy the W76-2 warhead in late January 2020.
John Rood, then the Undersecretary of Defense for Policy, confirmed the deployment in early
February, noting that “the warhead will help the United States dissuade Russia from risking
launching a limited nuclear conflict.”105
Several questions came up during the W76 life extension program. For example, some weapons
experts questioned whether the warhead’s design is reliable enough to ensure that the warheads
will explode at its intended yield.106 In addition, in June 2006, an inspector general’s report from
the Department of Energy questioned the management practices at the National Nuclear Security
Administration (NNSA), which is responsible for the LEP, arguing that management problems
had led to delays and created cost overruns in the program. This raised questions about whether
NNSA would be able to meet the September 2007 delivery date for the warhead,107 and, when
combined with other technical issues, delayed the delivery of the first W76 warhead until August
2008. The Navy accepted the first refurbished warhead into the stockpile in August 2009.108
W88 Alteration Program
While most Trident II missiles carry W76 warheads, a portion of the fleet carries the W88
warhead. This warhead, the last to be added to the U.S. nuclear stockpile, entered the force in the
late 1980s. According to DOE, this warhead is also in need of work to address concerns with its
safety and reliability. In particular, according to recent testimony, the W88 warhead is in the
“development engineering phase for Alteration (ALT) 370 to replace the aging arming, fuzing,
and firing components.” In August 2014, the Nuclear Weapons Council also decided to address
potential problems with the warhead’s conventional high explosive during the ALT 370 program.
This program received $169.5 million in FY2014, $165.4 million in FY2015, and $220.1 million
in FY2016. In its FY2016 budget request, NNSA indicated that the additional funding for this
program will come from offsets generated by reducing sustainment activities and the quantities of
stored warheads for some other types of warheads. In essence, NNSA “identified areas where
increased risk could be accepted to produce cost-savings within the current program—without
additional funding—and without additional delays to future work.”109 NNSA received $281.1
million for the W88 Alteration in FY2017. It requested $332.3 million for FY2018, $304.3
million in FY2019, and $304.2 million in FY2020. Congress enacted these amounts. NNSA has
requested $256.9 million for the W88 Alternation in FY2021 and $207.1 million in FY2022.
According to NNSA budget documents, this program was scheduled to produce its first
production unit (FPU) in 2020. However, in May 2019, NNSA indicated that the delivery of the
first production unit would slip after it identified defects in the electrical capacitors used in the
modified warheads. NNSA’s Kansas City National Security Campus, which acquires the
nonnuclear parts of nuclear weapons, had determined that the capacitors might not remain reliable
105 Robert Burns, “US adds ‘low yield’ nuclear weapon to its submarine arsenal,” Associated Press, February 4, 2020,
https://apnews.com/b910d5f4f2076d558416ae021b511517.
106 Fleck, John. Flaws Seen in Sub-Launched Nuclear Warhead. Albuquerque Journal. July 8, 2004.
107 Costa, Keith J. IG: Project Weaknesses put W-76 Warhead Refurbishment Plan at Risk. InsideDefense.com, June 8,
2006.
108 “Navy Receives First Refurbished W-76 Warheads,” Global Security Newswire, November 6, 2009.
109 Ibid.
Congressional Research Service
31
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
for 30-year life of the modified warheads. As a result, NNSA planned to replace the capacitors
that cost about $5 per unit with $75 units built to a higher standard. This is likely to add about
$120-$150 million to the cost of the W88-Alt LEP.110
In mid-July 2021, NNSA announced that it had “successfully completed the system-level First
Production Unit for the W88 Alteration (Alt) 370” on July 1, 2021. Although delayed past the
expected FY2020 date, NNSA noted that it had completed this FPU one month ahead of the date
planned in the adjusted schedule.111
W93 Warhead and MK7 Aeroshell
In its FY2021 budget request, NNSA requested $53 million to begin Phase 1 “concept assessment
and refinement” activities for a new W93 warhead. NNSA and the Navy have indicated that the
W93 sea-based warhead will eventually replace the W76 and W88 warheads on life-extended
Trident II missiles. In the past, NNSA documents had referred to this warhead as the “next Navy
warhead.” NNSA had not expected to request funding for it until FY2023. A DOD official noted
that because the warhead does not yet exist, this is not a life extension program, but neither
NNSA nor DOD has designated this as a “new” warhead. The Pentagon has indicated, however,
that it will be a “new program of record,” and will be based on previously nuclear-tested designs.
Therefore, it will not require nuclear testing.112
NNSA indicated that the program for this new warhead would follow the Phase 1 through 7
nuclear weapons acquisition cycle system113 during its development process. Congress, in the
FY2021 NDAA Conference Report (H.Rept. 116-617), outlined a number of reporting and
assessment requirements designed to strengthen oversight and ensure adequate program
management. These include reports on the planned characteristics of the warhead; assessments of
the requirements that the warhead might generate for the nuclear weapons enterprise; a plan to
implement a process of independent peer review of the warhead’s characteristics; and a report on
the requirements for the numbers and types of warheads that will be deployed on the U.S. SSBN
force.
NNSA requested $53 million to begin studies on the W93 warhead in FY2021; Congress
authorized this amount. The Navy also plans to design a new reentry body, known as the MK7
aeroshell, that would house the new warhead when it is deployed on Trident II missiles. It
requested $32 million for this effort in FY2021, and expects to request a total of $480 million
over the next five years.114 NNSA requested $72 million for the W93 warhead in FY2022, with
110 Dan Leone, “Balky Capacitors Could Delay Two NNSA Nuke Refurb Programs,” Nuclear Security and Deterrence
Monitor, May 10, 2019, https://www.exchangemonitor.com/balky-capacitors-delay-two-nnsa-nuke-refurb-programs/.
See, also, Aaron Mehta, “How a $5 part used to modernize nuclear warheads could cost $850 million to fix,” Defense
News, September 25, 2019, https://www.defensenews.com/smr/nuclear-arsenal/2019/09/25/nuclear-warhead-programsneed-850m-fix-heres-how-the-government-plans-to-cover-it/?utm_source=Sailthru&utm_medium=email&
utm_campaign=EBB%2009.26.19&utm_term=Editorial%20-%20Early%20Bird%20Brief.
111 National Nuclear Security Administration, NNSA completes First Production Unit of W88 Alteration 370,
Washington, DC, July 13, 2021, https://www.energy.gov/nnsa/articles/nnsa-completes-first-production-unit-w88alteration-370.
112 Aaron Mehta, “Inside America’s newly revealed nuclear ballistic missile warhead of the future,” Defense News,
February 24, 2020, https://www.defensenews.com/smr/nuclear-arsenal/2020/02/24/inside-americas-newly-revealednuclear-ballistic-missile-warhead-of-the-future/?utm_source=Sailthru&utm_medium=email&utm_campaign=
EBB%2002.25.20&utm_term=Editorial%20-%20Early%20Bird%20Brief.
113 U.S. Department of Energy, Nuclear Weapons Life Cycle, Fact Sheet, Washington, DC, September 2015,
https://www.energy.gov/sites/prod/files/2018/06/f53/6x%20process.pdf.
114 Jon Harper, “Political Battle Brewing Over New Nuclear Program,” National Defense, March 17, 2020,
Congressional Research Service
32
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
the program transitioning from the Phase 1 concepts study to Phase 2, where NNSA and will
review the concepts and provide a specific set of design options. It also requested $62 million to
continue work on the MK7 aeroshell.
The Columbia Class Submarine
The Navy is currently completing design work and beginning procurement of a new class of
ballistic missile submarines, known as the Columbia Class. This was originally known as the
SSBN(X) program and the Ohio Replacement Program (ORP). These submarines will replace the
Ohio-class Trident submarines as they reach the end of their service lives.115 The Trident
submarines will begin to retire in 2027, and the Navy initially indicated that it would need the
new submarines to begin to enter the fleet by 2029, before the number of Trident submarines falls
below 12.116 To do this, the Navy would have had to begin construction of its new submarine by
2019 so that it could begin to enter the fleet in 2029.117 However, in the FY2013 budget request,
the Navy delayed the procurement of the new class of submarines by two years. As a result, the
first new submarine will enter the fleet in 2031 and the number of SSBNs in the fleet is expected
to decline to 10 for most of the 2030s.
Costs and Funding
The SSBN(X) program received $497.4 million in research and development funding in the
Navy’s FY2010 budget. The Navy requested an additional $672.3 million in research and
development funding for the program in its FY2011 budget proposal. The FY2012 budget
included $1.07 billion to develop the SSBN(X). It expected to request $927.8 million in FY2013,
with the funding of $29.4 billion between 2011 and 2020. However, with the delay of two years
in the procurement of the first SSBN(X), the Navy budgeted only $565 million for the program in
FY2013. It then budgeted $1.1 billion for FY2014 and $1.2 billion in FY2015. It received an
additional $1.39 billion in FY2016, with $971.4 million allocated to submarine development and
$419.3 million allocated to power systems.
The Navy requested an additional $1.9 billion for the Ohio-replacement (ORP) in FY2017.
Within this total, $700.1 million was allocated to submarine development and $390.3 million was
allocated to nuclear power systems. The Navy also requested $773.1 million for advanced
procurement; this funding will support detailed design work in preparation for the beginning of
construction. Both the House and the Senate authorized the requested levels of funding in their
versions of the 2017 Defense Authorization Bill. The House, however, moved the $773.1 million
for advanced procurement from the Navy’s shipbuilding budget into the congressionally created
National Sea-based Deterrent Fund (NSDF), which is described below. Congress approved the
full funding requests in the FY2017 National Defense Authorization Act (P.L. 114-328), but did
not transfer funding for advanced procurement to the NSDF. The Navy requested $1.9 billion for
the Columbia class submarine in FY2018, with $776.2 million for submarine development,
$265.5 million for advanced nuclear power systems, and $842.9 million for advanced
https://www.nationaldefensemagazine.org/articles/2020/3/17/political-battle-brewing-over-new-nuclear-program.
115 For details on this program, see CRS Report R41129, Navy Columbia (SSBN-826) Class Ballistic Missile Submarine
Program: Background and Issues for Congress, by Ronald O'Rourke.
116 Christopher J. Castelli, “Navy Confronts $80 Billion Cost of New Ballistic Missile Submarines,” Inside Defense,
November 3, 2009.
117 RADM Stephen Johnson, Director, Navy Strategic Programs Office. Speech at the NDU/NDIA Seminar Series,
June 23, 2009.
Congressional Research Service
33
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
procurement. Congress approved this request in the National Defense Authorization Act for
FY2018 (H.Rept. 115-404).
The Navy requested $3.8 billion for the Columbia Class submarine in its FY2019 budget. Within
this total, $514.8 million was allocated to submarine development, $256.1 million to advanced
nuclear power systems, and $3 billion to advanced procurement. Congress authorized $526.8
million for submarine development and $3.2 billion for advanced procurement in the National
Defense Authorization Act for Fiscal Year 2019 (P.L. 115-232). According to the Navy’s budget
documents, the FY2019 request is “predominantly driven by procurement of the two-year long
lead time” of equipment needed to begin construction of the first submarine. This equipment
includes launcher and fire control subsystem components, nuclear propulsion plant equipment,
and hull mechanical and electrical systems. According to the Navy, “these funds are required in
October of 2018 to ensure the Columbia Program meets program schedules and the components
will meet contractor in yard need dates to support on time construction start and delivery of the
lead ship.” Moreover, within the $3 billion requested for advanced procurement, the largest single
amount ($1.7 billion) is allocated to the “nuclear propulsion plant equipment”—the nuclear
reactor that will power the submarine.
The Navy requested $2.23 billion for the Columbia Class submarine in its FY2020 budget. Within
this total, $551 million is allocated to research and development, $1.7 billion is allocated to
advanced procurement. In addition, the NNSA budget contains $75 million for the development
of the nuclear reactor for the submarine. The House, in its version of the FY2020 National
Defense Authorization Bill, increased funding for advanced procurement to $1.824 billion, and
the Senate increased funding for research and development to $548.1 million. Congress approved
$1.822 billion for advanced procurement and $548.1 million for research and development in the
FY2020 National Defense Authorization Act (P.L. 116-92).
The Navy requested $4.4 billion for the Columbia Class submarine in its FY2021 budget. While
this is a 90% increase over the request for FY2020, it is consistent with the funding level that
planned for FY2021, with significant funding now going toward procurement. Within the $4.4
billion total, the Navy allocated $397 million to research and development, $1.1 billion to
advanced procurement, and $2.9 billion to procurement. In addition, the NNSA budget contained
$64.7 million for the development of the nuclear reactor for the submarine. Congress, in the
conference report on the FY2021 National Defense Authorization Act (H.Rept. 116-617),
generally approved the Navy’s request but added $130 million to the funding for advanced
procurement. The conference report notes that this added funding was intended to support the
expansion of the submarine industrial base to ensure that second- and third-tier contractors can
meet increased production requirements as the procurement phase of the program proceeds.
The Navy requested $4.65 billion for the Columbia class submarine in its FY2021 budget. Within
this total it has allocated $1.65 billion to advanced procurement and $3 billion to procurement. In
addition, the NNSA budget requests $55 million for the development of the reactor for the
submarine. The Navy again requested $4.65 for procurement and advanced procurement in
FY2022; Congress has authorized $4.78 billion.
The Navy had planned to begin the detailed design for the submarine and to begin advanced
procurement of critical components in FY2015, with the seven-year construction period for the
first submarine beginning in FY2019. This timeline changed, in part to reduce near-term costs,
but also to reduce risks in the program. With advanced procurement beginning in FY2017, the
Navy plans to begin building the first hull in 2021. At the same time, it will continue to support
the joint U.S./U.K. development of a common missile compartment, which both nations will use
in their new SSBNs.
Congressional Research Service
34
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
The Navy initially estimated that each submarine in this program could cost $6 billion to $7
billion in FY2010 dollars. It has worked to redesign the submarine and reduce the costs, with the
plan to hold each submarine to around $4.9 billion, in FY2010 dollars. Officials in the Navy and
analysts outside government have expressed concerns about the cost of this program, and about
the effect that these costs may have on the rest of the Navy’s shipbuilding plans. A study by the
Congressional Budget Office indicated that the SSBN(X) program could cost a total of $97-$102
billion, in 2010 dollars, with $10-$15 billion for research and development and $87 billion for the
procurement of 12 submarines.118 A March 2015 GAO report assessing estimated the total
acquisition cost of the SSBN(X) program at about $95.8 billion, in constant FY2015 dollars,
including about $11.8 billion in research and development costs and about $84.0 billion in
procurement costs.119 More recently, the Navy has estimated that the first submarine would cost
$13.2 billion in 2018 dollars and that subsequent ships would have an average cost of $6.6
billion, for a total acquisition cost of $85 billion for 12 submarines. With research and
development costs of $13 billion, the total acquisition cost would be $98 billion.120
There has been widespread agreement, in the Navy, at the Pentagon, and among defense analysts,
that the costs associated with the Columbia class submarine could affect the rest of the Navy’s
shipbuilding budget. At one point, Navy officials estimated that, if the Navy funded this program
through its current, planned shipbuilding budget, it would have to forgo the acquisition of up to
32 other naval vessels. According to former Navy Secretary Ray Mabus, unless Congress
provides extra funding, “the production of 12 new ships to replace the Ohio-class submarines
could ‘gut’ the Navy’s shipbuilding budget for more than a decade.”121 In testimony before
Congress in February 2015, Navy officials noted that “the Navy continues to need significant
increases in our topline beyond the FYDP [Future Years Defense Plan] … in order to afford the
OR [Ohio replacement] SSBN procurement costs. Absent a significant increase … OR SSBN
construction will seriously impair construction of virtually all other ships in the battle force:
attack submarines, destroyers, and amphibious warfare ships.”122
In response to this growing fiscal pressure, Admiral Richard Breckenridge suggested, in
testimony offered in 2013, that Congress set up an annual $4 billion supplemental fund outside
the Navy’s budget to help support this program.123 Several Members of Congress have supported
this proposal.124 Congress included language in the FY2015 National Defense Authorization Act
118 Congressional Budget Office, An Analysis of the Navy’s Fiscal Year 2014 Shipbuilding Plan, Washington, DC,
October 2013, p. 24, http://www.cbo.gov/publication/44655.
119 Government Accountability Office, Defense Acquisitions[:] Assessments of Selected Weapons Programs, GAO-15342SP, March 2015, p. 148.
120 CBO has calculated the acquisition cost, excluding research and development, at $93 billion. See Congressional
Budget Office, An Analysis of the Navy’s Fiscal Year 2019 Shipbuilding Plan, Washington, DC, October 2018, p. 18,
https://www.cbo.gov/system/files?file=2018-10/54564-FY19Shipbuilding.pdf.
121 Yasmin Tadjdeh, “Mabus: Ohio-Class Submarine Replacement Could ‘Gut’ Navy Shipbuilding Budget,” National
Defense, September 15, 2014, http://www.nationaldefensemagazine.org/blog/Lists/Posts/Post.aspx?List=
7c996cd7%2Dcbb4%2D4018%2Dbaf8%2D8825eada7aa2&ID=1601.
122 Statement of the Honorable Sean J. Stackley, Assistant Secretary of the Navy (Research, Development and
Acquisition) and Vice Admiral Joseph P. Mulloy, Deputy Chief of Naval Operations for Integration of Capabilities and
Resources and Lieutenant General Kenneth J. Glueck Jr., Deputy Commandant, Combat Development and Integration
& Commanding General, Marine Corps Combat Development Command, Before the Subcommittee on Seapower and
Projection Forces of the House Armed Services Committee on Department of the Navy Seapower and Projection
Forces Capabilities, February 25, 2015, p. 8.
123 Lee Hudson, “Navy Asks Congress To Set Up Supplemental Fund for SSBN(X),” InsideDefense.com, September
12, 2013.
124 “Some U.S. Lawmakers Eye Funding new Submarines Outside Normal Process,” Global Security Newswire, March
Congressional Research Service
35
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
establishing a National Sea-based Deterrence Fund (P.L. 113-291, §1022). According to the
legislation, money placed in the fund will be available for the design, construction, purchase,
alteration, and conversion of “national sea-based deterrence vessels,” which is a reference to
ballistic missile submarines. The legislation also states that the Secretary of Defense has the
authority to transfer up to $3.5 billion into the fund from unobligated funds in the DOD budget.
Congress did not, however, appropriate increased funding for this effort, and the Secretary of
Defense had not identified or transferred any money into this fund. In the FY2016 NDAA, (H.R.
1735, §1051), Congress expanded the authority to transfer funding and included provisions
allowing the Secretary of the Navy to enter into “economic order quantity contracts” that might
achieve economic efficiencies based on production economies for major components or
subsystems. Some analysts estimate that this provision could reduce the procurement costs for the
submarine, saving, perhaps, several hundred million dollars per submarine.125
Most experts agree that, without increased appropriations, this fund may protect the Navy’s
shipbuilding budget from the costs of the Columbia class submarine, but that it would not really
solve the DOD’s problem, because the money for the fund would have to come from other
portions of the Pentagon budget.126 Nevertheless, the Navy continues to support the Columbia
class submarine as its highest priority, with Admiral John Richardson, the Chief of Naval
Operations, noting that the ballistic missile submarine force is “foundational to our survival.”127
Force Posture
The Navy designed the Columbia Class submarines with only 16 ballistic missile launch tubes.
The existing Trident submarines have 24 launch tubes, and each has been reduced to 20 missiles
as the United States complies with the New START Treaty. Congress questioned the Navy on this
plan during hearings in April 2011, with some Members asking whether the United States would
be able to deploy enough warheads if it reduced the numbers of missiles on each submarine.
Admiral Terry Benedict, then the Director of the Navy’s Strategic Systems Program Office,
testified that the Navy’s ability to “upload” warheads onto Trident missiles convinced him, along
with other Navy and STRATCOM officials, that they could be comfortable with this
configuration.128
A report published in late 2011 indicated that the Office of Management and Budget (OMB)
suggested that the Navy reduce the number of SSBNs in the fleet to 10, but increase the number
of launch tubes on each submarine to 20.129 According to the OMB analysis, this could save the
Navy $7 billion over the life of the fleet, by reducing acquisition costs and operating costs. It
would not, however, undermine the submarines’ mission because, with 20 missiles per submarine,
the Navy would still be able to cover the full range of targets assigned to the Trident fleet.
Analysts outside government have offered similar suggestions, noting that the Navy could save
12, 2014. See, also, Lee Hudson, “House Committee Looks to Create Separate Fund for Ohio Replacement,”
InsideDefense.com, May 2, 2014.
125 Eric Laws, An Analysis of the Navy’s Fiscal Year 2016 Shipbuilding Plan, Congressional Budget Office,
Washington, DC, October 2015, pp. 18-19, https://www.cbo.gov/sites/default/files/114th-congress-2015-2016/reports/
50926-Shipbuilding_OneCol-2.pdf.
126 Kingston Reif, “Hill Denies Money for Submarine Fund,” Arms Control Today, January 2016.
http://www.armscontrol.org/ACT/2016_0102/News/Hill-Denies-Money-for-Submarine-Fund.
127 Robert Burns, “New Navy Leader: Nukes ‘Foundational to Our Survival,’” Associated Press, January 7, 2016.
128 Emelie Rutherford, “Navy Defends Plan for Just 16 Missile Tubes on Next Boomer,” Defense Daily, April 7, 2011.
129 Colin Clark, “OMB Pushes More Tubes, Fewer Boats for Ohio Replacement Subs,” AOL Defense, November 4,
2011, http://defense.aol.com/2011/11/04/omb-pushes-more-tubes-fewer-boats-for-ohio-replacement-subs/.
Congressional Research Service
36
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
$27 billion over 10 years and $120 billion over the life of the fleet if the Navy built 8, rather than
12 submarines.130 Moreover, according to this analysis, the Navy would be able to deploy the
necessary number of warheads on these submarines, even if it did not increase the number of
launch tubes, by deploying more warheads on each of the Trident missiles on the submarine.
Generally, the number of launch tubes on the submarines should not affect the number of
warheads carried by each submarine or the ability of the fleet to hold a range of potential targets
at risk. Trident missiles can be equipped with eight warheads each, but, in their current
configuration, the missiles likely carry, on average, only three or four warheads each, as the force
was reduced to the levels in New START. If the new submarines carry only 16 missiles, rather
than the 20 planned under New START, then they could deploy with 5-6 warheads per missile. In
essence, the Navy would put the same number of warheads on each submarine, but would just
spread them over a smaller number of missiles.
The Navy has noted that, as the United States reduces its forces to New START levels, the lower
number of missiles per submarine will allow the United States to retain a larger number of
submarines, without exceeding the treaty’s limit of 700 operational delivery vehicles. This allows
the Navy to maintain a fleet of 12 submarines, and to operate those submarines with continuous
deployments from 2 bases. The Navy has argued that, if it reduces the numbers of submarines in
the fleet, and alters its deployment patterns, it will not be able to meet its requirements, as these
cover more than just the total number of warheads on the fleet or total number of warheads at sea
at any time. Critics outside the government, however, question this approach, both because a fleet
of 12 submarines will cost more to procure and operate than a fleet of only 8 submarines and
because this fleet presumes that the United States must retain its current pattern of operations for
the SSBN fleet for the next 50-60 years.
With 12 submarines in the fleet, the Navy can maintain 4-5 on station at any time, patrolling in
areas where they would need to be to launch their missiles promptly after a presidential order.
But, in the past, some critics questioned whether this pattern, and the “continuous at-sea”
deterrent of 4-5 submarines, would be necessary in the decades ahead. They noted that the United
States would be able to maintain a secure second strike deterrent on the submarines, even if they
cannot launch as many warheads promptly as they can launch today. Others however, have
continued to support the current operational patterns, and to argue for a fleet of at least 12
submarines into the future. Congress, in the FY2013 Defense Authorization Bill (P.L. 112-239,
§130) stated that “the continuous at-sea deterrence provided by a robust and modern fleet of
nuclear-powered ballistic missile submarines is critical to maintaining nuclear deterrence and
assurance and therefore is a central pillar of the national security of the United States.” The
legislation went on to indicate that “a minimum of 12 replacement ballistic missile submarines
are necessary to provide continuous at-sea deterrence over the lifetime of such submarines.”
Bombers
B-1 Bomber
The Air Force began to deploy the B-1 bomber in the mid-1980s and eventually deployed a fleet
of 96 aircraft. After several crashes, the Air Force was left with 92 bombers in 2001. It sought to
retire 30 of the aircraft, leaving a force of 62 bombers, but that plan met resistance from
Congress. The B-1 served exclusively as a nuclear delivery vehicle through 1991, carrying shortrange attack missiles and gravity bombs. Because these bombers were not equipped to carry
130 Tom Collina and Kelsey Davenport, “U.S. Must Rethink New Subs, Bombers,” Defense News, October 24, 2011.
Congressional Research Service
37
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
nuclear-armed air-launched cruise missiles, each counted as a single delivery vehicle and a single
warhead under START. In 1993, the Air Force began to convert the B-1 bombers to carry
conventional weapons. Specifically, the Air Force welded a metal sleeve onto each of the pylon
attachments under the bomber’s wings, which prevented them from carrying air-launched cruise
missiles.131 This process was completed in 1997 and the B-1 bomber is no longer equipped to
carry nuclear weapons. In 2011, the United States displayed the bomber to the Russians, under
the terms of the New START Treaty, to demonstrate that it was no longer equipped to deliver
nuclear weapons and to confirm that it would not count under the limits in New START. The
bomber has contributed to U.S. conventional operations in Afghanistan and Iraq and contributed
to reassurance missions in Asia.
In December 2020 the Air Force conducted a flight test during which a B-1 bomber demonstrated
the ability to carry and release a JASSM cruise missile from an external pylon. They pylon used
in this demonstration was not one of the under-wing pylons that had been covered as part of the
bomber conversion. Air Force officials noted, however, that the goal was to eventually expand the
use of the external pylons on the B-1 bombers to “increase the operational flexibility of the
bomber fleet.”132 A representative for Air Force asserted that the use of the under-wing pylons to
carry cruise missiles or hypersonic weapons would not violate the New START Treaty because
the missiles would carry conventional warheads. However, when the pylons were covered, the
goal was to remove the bombers from accountability under the treaty. This accountability was
based on an assessment of whether the bomber could carry nuclear-armed cruise missiles, not
whether it was actually equipped with those missiles.
B-2 Bomber
The Air Force has 20 B-2 bombers, which are based at Whiteman AFB in Missouri.133 The B-2
bomber can carry both B61 and B83 nuclear bombs, but is not equipped to carry cruise missiles.
It can also carry conventional weapons and has participated in U.S. military campaigns from
Bosnia to Iraq. It is designed as a “low observable” aircraft and was intended to improve the U.S.
ability to penetrate Soviet air defenses. It continues to serve as a penetrating bomber, both when
flying conventional missions and when supporting the nuclear deterrent mission. The Air Force
has indicated that it needs significant maintenance and modernization funding to support the
mission.134
Weapons
According to unclassified estimates, the United States has around 322 B61 and B83 bombs for
use by strategic bombers, and an additional 230 B61 bombs for use by fighter aircraft.135 The B61
131 Valerie Insinna, “The B-1B just launched a cruise missile externally. Hypersonic missiles could be next.,” Defense
News, December 9, 2020, https://www.defensenews.com/air/2020/12/09/the-b-1b-just-launched-a-cruise-missileexternally-hypersonic-missiles-could-be-next/?utm_source=Sailthru&utm_medium=email&utm_campaign=
EBB%2012.10.20&utm_term=Editorial%20-%20Early%20Bird%20Brief.
132 Giancarlo Casem, B-1B Lancer completes successful external release demonstration, Air Force Global Strike
Command, Edwards Air Force Base, CA, December 9, 2020, https://www.afgsc.af.mil/News/Article-Display/Article/
2441552/b-1b-lancer-completes-successful-external-release-demonstration/.
133 A B-2 bomber crashed on take-off from Anderson Air Force Base on Guam in late February 2008, reducing the
number of deployed bombers from 21 to 20.
134 For details on the ongoing programs supporting this bomber and the B-52 bomber, see CRS Report R43049, U.S.
Air Force Bomber Sustainment and Modernization: Background and Issues for Congress, by Jeremiah Gertler.
135 Hans M. Kristensen and Matt Korda, “U.S. Nuclear Forces, 2021,” Bulletin of the Atomic Scientists, January, 2021,
Congressional Research Service
38
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
contains a number of different versions. The B61-7 serves as a strategic bomb and is carried by
B-2 bombers. The B61-3, 4, and 10 are considered nonstrategic bombs, with lower yields, and
would be delivered by fighter aircraft like the F-16 and F-35. The B61-11, a modification
developed in the 1990s, has a hardened, modified case so that it can penetrate some hardened
targets, although probably not those encased in steel and concrete. The B61-Mod 7, along with
the Mod-3 and Mod-4, and Mod-10 versions, are a part of an ongoing life extension program
(LEP) that will produce a new B61-mod 12 bomb.136 According to the Department of Energy,
NNSA completed the first production unit of the B61-12 on November 23, 2021.137
During the Obama Administration, NNSA announced that it planned to retire the B83, the largest
bomb remaining in the U.S. arsenal, around 2025, after the completion of the B61 LEP. The
Trump Administration, in the 2018 Nuclear Posture Review, altered that plan, announcing in the
2018 Nuclear Posture Review that it will sustain “the B83-1 past its currently planned retirement
date until a suitable replacement is identified.”138 The Biden Administration has not yet altered
this plan, with NNSA requesting $98.5 million for B83 sustainment in FY2022. Although the
House did not include funding for this program in its version of the FY2022 NDAA, Congress
has authorized this funding in the final version of the bill (S. 1605).
The Obama Administration strongly supported the life extension program for the B-61 bomb in
the 2010 Nuclear Posture Review. The report indicated that “the Administration will fully fund
the full scope LEP study and follow-on activities for the B61 bomb ...
This text is long and has been trimmed here. Open the source document for the complete record.
This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.