High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

Congressional research reportJul 21, 2008

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High Altitude Electromagnetic Pulse (HEMP)

and High Power Microwave (HPM) Devices:

Threat Assessments

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July 21, 2008

Congressional Research Service

7-....

www.crs.gov

RL32544

CRS Report for Congress

Prepared for Members and Committees of Congress

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

Summary

Electromagnetic Pulse (EMP) is an instantaneous, intense energy field that can overload or

disrupt at a distance numerous electrical systems and high technology microcircuits, which are

especially sensitive to power surges. A large scale EMP effect can be produced by a single nuclear

explosion detonated high in the atmosphere. This method is referred to as High-Altitude EMP

(HEMP). A similar, smaller-scale EMP effect can be created using non-nuclear devices with

powerful batteries or reactive chemicals. This method is called High Power Microwave (HPM).

Several nations, including reported sponsors of terrorism, may currently have a capability to use

EMP as a weapon for cyber warfare or cyber terrorism to disrupt communications and other parts

of the U.S. critical infrastructure. Also, some equipment and weapons used by the U.S. military

may be vulnerable to the effects of EMP.

The threat of an EMP attack against the United States is hard to assess, but some observers

indicate that it is growing along with worldwide access to newer technologies and the

proliferation of nuclear weapons. In the past, the threat of mutually assured destruction provided a

lasting deterrent against the exchange of multiple high-yield nuclear warheads. However, now

even a single, low-yield nuclear explosion high above the United States, or over a battlefield, can

produce a large-scale EMP effect that could result in a widespread loss of electronics, but no

direct fatalities, and may not necessarily evoke a large nuclear retaliatory strike by the U.S.

military. This, coupled with published articles discussing the vulnerability of U.S. critical

infrastructure control systems, and some U.S. military battlefield systems to the effects of EMP,

may create a new incentive for other countries to rapidly develop or acquire a nuclear capability.

Policy issues raised by this threat include (1) what is the United States doing to protect civilian

critical infrastructure systems against the threat of EMP, (2) could the U.S. military be affected if

an EMP attack is directed against the U.S. civilian infrastructure, (3) are other nations now

encouraged by U.S. vulnerabilities to develop or acquire nuclear weapons, and (4) how likely are

terrorist organizations to launch a smaller-scale EMP attack against the United States?

This report will be updated as events warrant.

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High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

High Altitude Electromagnetic Pulse (HEMP) and

High Power Microwave (HPM) Devices: Threat

Assessments

Background ................................................................................................................................1

The EMP Commission ..........................................................................................................2

2008 Report on Critical Infrastructure Vulnerabilities ............................................................3

Private Sector and State Government Poorly Prepared...........................................................3

Inaction May Increase EMP Threat to the United States.........................................................4

Electromagnetic Pulse Overview...........................................................................................5

Description of High-Altitude Electromagnetic Pulse..............................................................5

Description of High-Power Microwaves................................................................................7

Disruptive Effects of EMP ....................................................................................................8

Recovery After Attack...........................................................................................................9

Economic Damage Estimates after Attack on Washington, D.C., Region ...............................9

Portable Data Centers and Hardening Against EMP............................................................. 11

DOD Vulnerabilities and Research ...................................................................................... 12

Ground Wave Emergency Network ..................................................................................... 13

EMP Capabilities of Other Nations...................................................................................... 14

Policy Analysis ......................................................................................................................... 15

Preparedness ....................................................................................................................... 15

Department of Homeland Security ...................................................................................... 16

Nuclear Incentive................................................................................................................ 17

Terrorists............................................................................................................................. 17

Human Rights ..................................................................................................................... 18

Legislative Activity................................................................................................................... 18

CRS Products............................................................................................................................ 18

Tables

Table 1. Estimates of Damage and Recovery Times After HEMP Attack on Washington,

D.C., Regional Area ............................................................................................................... 10

Contacts

Author Contact Information ...................................................................................................... 19

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High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

Background

A Commission to Assess the Threat from High Altitude Electromagnetic Pulse (EMP

commission) was established by Congress in FY2001 after several experts expressed concern that

the U.S. critical infrastructure and military were vulnerable to EMP attack.1 On July 20, 2008, the

Commission presented a report to the House Armed Services Committee (HASC) assessing the

effects of an EMP attack on U.S. critical national infrastructures. The 2008 report contained

analysis of results of tests for modern electronics and telecommunications equipment for public

networks supported by the power grid and by temporary isolated power supplies, including cell

phones, computer servers, and Internet routers and switches. The report also made

recommendations for preparation, protection, and recovery of U.S. critical infrastructures from

EMP attack.

The Commission reported that the ubiquitous dependency of society on the electrical power

system, coupled with the EMP’s particular damage mechanisms, creates the possibility of longterm, catastrophic consequences for national security. Comparison was made to hurricane Katrina

in 2005, where the protracted power blackout exhausted the limited fuel supplies for emergency

generators. However, in the case of an EMP attack, a widespread collapse of the electric power

grid could lead to cascading effects on interdependent infrastructures, possibly lasting weeks or

months. The Commission stated, “Should significant parts of the electrical power infrastructure

be lost for any substantial period of time ... many people may ultimately die for lack of the basic

elements necessary to sustain life in dense urban and suburban communities ... [and] the Federal

Government does not today have sufficiently robust capabilities for reliably assessing and

managing EMP threats.”2

At a prior hearing, on July 22, 2004, panel members from the EMP commission stated that as

U.S. military weapons and control systems become more complex, and as portions of the

military’s administrative communications systems continue to rely on the U.S. civilian

infrastructure for support, they may be increasingly vulnerable to the effects of EMP. The

consensus of the Commission in 2004 was that a large-scale, high-altitude EMP attack could

possibly cause widespread damage to unprotected civilian and military electronic equipment for

an extended period.3

However, the consensus of the EMP commission in 2008 was that the United States need not

remain vulnerable to catastrophic consequences of an EMP attack, and that the nation’s

vulnerability can be reasonably reduced by coordinated and focused effort between the private

and public sectors. The Committee stated that the cost for improved security in the next three to

five years would be modest, especially when compared with the costs associated with the war on

terror and the value of the national infrastructures threatened. 4

Michael Sirak, “U.S. vulnerable to EMP Attack,” Jane’s Defence Weekly, July 26, 2004, http://www.janes.com/

defence/news/jdw/jdw040726_1_n.shtml.

Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack;

Critical National Infrastructures, April 2008, pp. vi-viii, and p. 79.

Daniel G. Dupont, “Panel Says Society At Great Risk From Electromagnetic Pulse Attack,” Inside the Pentagon, July

15, 2004, p.1.

William Graham, Testimony before the House Armed Services Committee, July 10, 2008.

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High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

The EMP commission’s reports in both 2004 and 2008 focused only on the effects of High

Altitude EMP (HEMP), and not necessarily the effects High Power Microwave (HPM) devices,

which are non-nuclear Radio-Frequency (RF) weapons that can also produce damaging EMP, but

with different characteristics and covering a smaller geographic area. Both types of EMP are

discussed below. The widely published vulnerability of U.S. civilian and some military

electronics to EMP, along with technical accessibility and lower cost, could make smaller-scale

HPM weapons attractive in the future as weapons for terrorist groups. Also, some observers argue

that unless the United States openly describes how it is taking action to reduce EMP

vulnerabilities within critical infrastructures, perceived inaction will increase the likelihood that a

rogue nation will seek to employ the asymmetric effects of HEMP against our computer systems.

The EMP Commission

The EMP commission was reestablished by P.L. 109-163, the National Defense Authorization Act

for FY2006. The new Commission to Assess the Threat to the United States from

Electromagnetic Pulse Attack (note that the new title no longer includes the phrase “High

Altitude”, and adds the new word “Attack”) continues with the same membership, and the

Secretary of Defense is authorized to appoint a new member in the event of a vacancy. 5 The EMP

commission is tasked to monitor, investigate, and make recommendations about the vulnerability

of electric-dependent systems of the Department of Defense, government agencies, and the

private sector.

On July 22, 2004, members of the EMP commission testified before the House Armed Services

Committee and presented a report consisting of the following five volumes:

Volume 1 is an unclassified Executive Summary.

Volume 2 is a classified Threat Assessment.

Volume 3 is an unclassified Assessment of the U.S. Critical Infrastructure.

Volume 4 is a classified discussion of Military Topics.

Volume 5 is a classified Assessment of Potential Threats.

The report stated that High Altitude EMP is capable of causing catastrophic consequences for the

nation, and that the current vulnerability of our critical infrastructures, which depend so heavily

on computers and electronics, can both invite and reward attack if not corrected. 6

Specifically referring to the U.S. military, the report states:

EMP test facilities have been mothballed or dismantled, and research concerning EMP

phenomena, hardening design, testing, and maintenance has been substantially decreased.

However, the emerging threat environment, characterized by a wide spectrum of actors that

include near-peers, established nuclear powers, rogue nations, sub-national groups, and

P.L. 109-163, Section 1052, reestablishes the EMP commission.

William Graham, et al., Report of the Commission to Assess the Threat to the United States from Electromagnetic

Pulse Attack, Volume 1: Executive Report 2004.

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High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

terrorist organizations that either now have access to nuclear weapons and ballistic missiles

or may have such access over the next 15 years have [sic] combined to place the risk of EMP

attack and adverse consequences on the U.S. to a level that is not acceptable.... Our

increasing dependence on advanced electronics systems results in the potential for an

increased EMP vulnerability of our technologically advanced forces, and if unaddressed

makes EMP employment by an adversary an attractive asymmetric option.”7

The EMP commission’s 2004 report proposed a five-year plan for protecting critical

infrastructures from EMP and from other large-scale terrorist attacks. The five-year plan is briefly

summarized in Volume 3 of the report. However, some portions of the five-year plan that are

related to military equipment may remain classified. The Commission is currently preparing a

review of the DOD response to recommendations made in 2004.8

Testimony at the 2004 hearing included questions such as (1) how would the United States

respond to a limited HEMP attack against the U.S. homeland or against U.S. forces, where there

is loss of technology, but no directly caused loss of life; (2) does the current lack of U.S.

preparedness invite adversaries to plan and attempt a HEMP attack; and (3) are the long-term

effects of a successful HEMP attack, leading to possible widespread starvation and population

reduction, potentially more devastating to the U.S. homeland than an attack by surface nuclear

weapons?

2008 Report on Critical Infrastructure Vulnerabilities

The 2008 EMP Commission report discussed vulnerabilities and interdependencies among 10

U.S. critical infrastructures. Findings showed that only limited EMP vulnerability testing had

previously been done for modern electronic systems that help support these infrastructures. In

addition, the Commission expressed concern that widespread use of automated supervisory and

control data acquisition (SCADA) systems for the critical infrastructure had allowed companies

and agencies to systematically reduce the size of their work forces having the necessary technical

knowledge needed to support manual operations of these infrastructure control systems, as might

be needed during a prolonged emergency. The Commission concluded, after reviewing national

capabilities to manage the effects of nuclear weapons (and EMP) on modern systems, that “the

Country is rapidly losing the technical competence in this area that it needs in the Government,

National Laboratories, and Industrial Community.”9

Private Sector and State Government Poorly Prepared

Experts on the Commission have asserted that little has been done by the private sector to protect

against the threat from electromagnetic pulse, and that commercial electronic systems in the

United States could be severely damaged by EMP attack.10 Commercial electronic surge arresters

commonly used for lightning strikes reportedly cannot be relied on because most do not clamp

William Graham, et al., Report of the Commission to Assess the Threat to the United States from Electromagnetic

Pulse Attack, Volume 1: Executive Report 2004, p. 47.

Personal communication with EMP Commission staff, March 26, 2008.

Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack;

Critical National Infrastructures, April 2008, p. viii.

House Armed Services Committee, Committee Hearing on Commission to Assess the Threat to the United States

from Electromagnetic Pulse Attack, July 22, 2004.

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fast enough to protect against the near-instantaneous effects of EMP (see section below on

“Electromagnetic Pulse Overview”). 11

In March 2007, a survey of state Adjutants General who oversee National Guard units throughout

the country found that most state-based emergency responders are not actively preparing against

an attack on the United States by electromagnetic pulse. The survey, entitled “Missile Defense

and the Role of the States”, was conducted jointly by the Anchorage-based Institute of the North

and the Claremont Institute of Claremont, California. Survey questions were sent to Adjutants

General of all 50 states, with more than half responding. Although 96% of state Adjutants General

indicated significant concern over an EMP attack, the majority had done little or no analysis of

the effects of an overhead EMP attack, and little or no training, or preparation to harden electronic

equipment. None of the Adjutants General surveyed indicated that they were actively involved in

a formal planning process for response to an EMP attack.12

Inaction May Increase EMP Threat to the United States

Some analysts discount the likelihood of a large-scale EMP attack against the United States in the

near term, and the extent of possible damage, stating that the critical infrastructure reportedly

would survive, and that military communications would continue to operate and a high

percentage of civilian phone calls would continue to connect. The argument is that limited testing

has shown that modern commercial equipment may be surprisingly resistant to the effects of

electromagnetic pulse, and that some military systems using commercial equipment are also

retrofitted to be made more EMP resistant before they are fielded. 13

However, other analysts maintain that some past testing done by the U.S. military may have been

flawed, or incomplete, leading to faulty conclusions about the level of resistance of commercial

equipment to the effects of EMP. These analysts also point out that EMP technology has been

explored by several other nations, and as circuitry becomes more miniaturized, modern

electronics become increasingly vulnerable to disruption. They argue that, depending on the

targeted area and power of an EMP attack, it could possibly take years for the United States to

recover fully from the resulting widespread damage to electronics and the power grid.14

Commission members have stated at hearings that, as time passes without a visible effort to show

the world that we are protecting our computer systems and critical infrastructures, the perceived

inaction may actually invite a possible EMP attack.15 In the past, the threat of mutually assured

Army Training Manual 5-692-2, “Maintenance of Mechanical and Electrical Equipment at Command, Control,

Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities, HEMP Protection

Systems, April 15, 2001, Chapter 27.

Press release, Survey Finds Nation Vulnerable to EMP Attack: States Not Preparing, Institute of the North and The

Claremont Institute, March 7, 2007, http://www.institutenorth.org/servlet/download?id=261.

Stanley Jakubiak, statement before the House Military Research and Development Subcommittee, hearing on EMP

Threats to the U.S. Military and Civilian Infrastructure, October 7, 1999.

Lowell Wood, Statement before the House Military Research and Development Subcommittee, hearing on EMP

Threats to the U.S. Military and Civilian Infrastructure, October 7, 1999; Jack Spencer, “America’s Vulnerability to a

Different Nuclear Threat: An Electromagnetic Pulse,” The Heritage Foundation Backgrounder, No.1372, May 26,

2000, p. 6.; and Carlo Kopp, “The Electromagnetic Bomb—A Weapon of Electrical Mass Destruction,” Air and Space

Power, 1993.

U.S. Congress, House Armed Services Committee, Committee Hearing on Commission to Assess the Threat to the

United States from Electromagnetic Pulse Attack, July 22, 2004, and on July 10, 2008.

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destruction provided a lasting deterrent against the exchange of multiple high-yield nuclear

warheads. However, a single, low-yield nuclear explosion high above the United States, or over a

battlefield, can produce a large-scale, high-altitude EMP effect resulting in widespread loss of

electronics, but possibly without direct fatalities. Therefore, an EMP attack directed against the

United States involving no violent destruction, nor instant death for large numbers of U.S.

citizens, may not necessarily evoke massive nuclear retaliation by the U.S. military, where, for

example, large numbers of innocent civilians of a nation with a rogue leader might be killed. Such

a perceived lower risk of assured destruction by the United States, and widespread knowledge

about the vulnerability of U.S. civilian and military computers to the effects of an EMP attack,

could actually create a new incentive for other countries or terrorist groups to develop, or perhaps

purchase, a nuclear capability.

Electromagnetic Pulse Overview

Electromagnetic energy, characterized as weapon potentially threatening to national security, can

be created as a pulse traditionally by two methods: overhead nuclear burst and microwave

emission. High-Altitude Electromagnetic Pulse (HEMP) is a near-instantaneous electromagnetic

energy field that is produced in the atmosphere by the power and radiation of a nuclear explosion,

and that is damaging to electronic equipment over a very wide area, depending on power of the

nuclear device and altitude of the burst. High-Power Microwave (HPM) electromagnetic energy

can be produced as a near-instantaneous pulse created through special electrical equipment that

transforms battery power, or powerful chemical reaction or explosion, into intense microwaves

that are also very damaging to electronics, but within a much smaller area. In addition, while

HEMP weapons are large in scale and require a nuclear capability along with technology to

launch high altitude missiles, HPM weapons are smaller in scale, and can involve a much lower

level of technology that may be more easily within the capability of some extremist groups. HPM

can cause damage to computers similar to HEMP, although the effects are limited to a much

smaller area.

Description of High-Altitude Electromagnetic Pulse

HEMP is produced when a nuclear weapon is detonated high above the Earth’s surface, creating

gamma-radiation that interacts with the atmosphere to create an instantaneous intense

electromagnetic energy field that is harmless to people as it radiates outward, but which can

overload computer circuitry with effects similar to, but causing damage much more swiftly than,

a lightning strike. 16 The effects of HEMP became fully known to the United States in 1962 during

a high-altitude nuclear test (code named “Starfish Prime”) over the Pacific Ocean, when radio

stations and electronic equipment were disrupted 800 miles away throughout parts of Hawaii. The

HEMP effect can span thousands of miles, depending on the altitude and the design and power of

the nuclear burst (a single device detonated at an appropriate altitude over Kansas reportedly

could affect all of the continental United States)17, and can be picked up by metallic conductors

A nuclear explosion produces gamma rays, which interact with air molecules in a process called the Compton effect.

Electrons are scattered at high energies, which ionizes the atmosphere, generating a powerful electrical field. This EMP

effect is strongest at altitudes above 30,000m, and lasts so briefly that current cannot start flowing through a human

body to cause harm to people.

The Federation of American Scientists, “Nuclear Weapons EMP Effects,” http://www.fas.org/nuke/intro/nuke/

emp.htm.

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High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

such as wires, or overhead power lines, acting as antennas that conduct the energy shockwave

into the electronic systems of cars, airplanes, or communications equipment.

Figure 1. Estimated Area Affected by High-Altitude

EMP

Source: Heritage Foundation, Jack Spencer, America’s Vulnerability to a Different Nuclear Threat: An Electromagnetic

Pulse, Backgrounder #1372, May 26, 2000, http://www.heritage.org/Research/MissileDefense/bg1372.cfm. Gary

Smith, “Electromagnetic Pulse Threats,” testimony before the House National Security Committee, July 16, 1997.

A high altitude nuclear explosion (that creates HEMP) produces three major energy components

that arrive in sequence, and which have measurably different effects that can be cumulatively

damaging to electronic equipment. The first energy component is the initial energy shockwave,

which lasts up to 1 microsecond, and is similar to extremely intense static electricity that can

overload circuitry for every electronic device that is within line of sight of the burst. A secondary

energy component then arrives, which has characteristics that are similar to a lightning strike. By

itself, this second energy component might not be an issue for some critical infrastructure

equipment, if anti-lightning protective measures are already in place. However, the rise time of

the first component is so rapid and intense that it can destroy many protective measures, allowing

the second component to further disrupt the electronic equipment.

The third energy component is a longer-lasting magnetohydrodynamic (MHD) signal, about 1

microsecond up to many seconds in duration. This late time pulse, or geomagnetic signal, causes

an effect that is damaging primarily to long-lines electronic equipment.

There are two components to this third late time energy pulse, which experts call “blast” and

“heave.” The “blast” results from a distortion of the earth’s magnetic field lines by the expanding,

fully conductive fireball. The “heave” comes from the heating and ionization of a patch of

atmosphere directly below the bomb that rises and, being conductive, also distorts the earth’s

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High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

magnetic field. Both of these are considered MHD signals and are termed “slow” because they

depend on the dynamics of cloud or fireball expansion.

As the fireball expands, a localized magnetic effect builds up on the ground throughout the length

of long transmission lines and then quickly collapses, producing the MHD “late-time” power

surge, which can overload equipment connected to the power grid and telecommunications

infrastructure. This late-time effect can add to the initial HEMP effect, and systems connected to

long-lines power and communications systems may be further disrupted by the combined effects.

Smaller isolated systems do not collect so much of this third energy component, and are usually

disrupted only by the first energy component of HEMP.18

It is also important to note that this third, late-time pulse depends on the total energy of the

nuclear detonation and therefore is usually associated only with larger yield nuclear weapons.

However, the first energy pulse is a saturation-limited effect and is produced by all nuclear

weapons, both small and large yield.

Description of High-Power Microwaves

Microwaves are characterized by electromagnetic energy with wavelengths as small as

centimeters or millimeters, and can be used at moderate power levels for radio frequency

communications or for radar.19 High-power microwaves can be created as an instantaneous

electromagnetic pulse, for example, when a powerful chemical detonation is transformed through

a special coil device, called a flux compression generator, into an intense electromagnetic field.20

Other methods can also be used to create a reusable HPM weapon, such as combining reactive

chemicals or using powerful batteries and capacitors to create EMP. HPM energy can be focused

using a specially-shaped antenna, or emitter, to produce effects similar to HEMP within a

confined area, or over a limited distance. Unlike HEMP, however, HPM radiation uses shorter

wave forms at higher-frequencies which make it highly effective against electronic equipment

and more difficult to harden against. A mechanically simple, suitcase-sized device, using a

chemical explosive and special focusing antenna, might theoretically produce a one-time,

instantaneous HPM shockwave that could disrupt many computers within a 1-mile range.21 Also,

HPM energy at higher power levels (megawatts), and powered for a longer time interval,

reportedly could cause physical harm to persons near the source emitter, or possibly in the path of

a narrowly focused energy beam. 22

The Federation of American Scientists, “Nuclear Weapons EMP Effects,” http://www.fas.org/nuke/intro/nuke/

emp.htm, and Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP)

Attack, Vol.1: Executive Report 2004, p.5.

For example, microwaves with wavelengths about 5.7 cm long (C-band), or 20 cm long (L-band), or 3 cm long (Xband) are often used for radar or communications.

A Flux Compression Generator consists of explosives packed inside a cylinder, all of which is contained within a

cylindrical copper coil structure. The explosive is detonated from rear to front, causing the tube to flare in a wave that

touches the copper coil, which produces a moving short circuit. This compresses the magnetic field and creates an

electromagnetic pulse that is emitted from the front end, which is then directed by a special focusing antenna.

Dr. Robert C. Harney, Naval Postgraduate School, April 12, 2004, personal communication.

Victorino Matus, “Dropping the E-bomb,” The Weekly Standard, February 2, 2003, http://theweeklystandard.com/

Utilities/printer_preview.asp?idArticle=2209&R=9F0C225C3.

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Disruptive Effects of EMP

Studies related to the effects of electromagnetic energy used as weapons have been published

infrequently, or remain classified. 23 Nevertheless, it is known that a powerful HEMP field as it

radiates outward can interfere with radio frequency links and instantly produce damaging voltage

and currents in electronic devices thousands of miles from the nuclear explosion. Effectiveness is

increased if the electronic devices are connected to any other metal that could also act as an

antenna. Because infrastructure computer systems are interconnected, a widespread HEMP effect

could lead to possible long-term disruption of the power grid, fuel distribution, transportation

systems, food and water supplies, and communications and equipment for hospitals and first

responders, as well as military communications systems which utilize the civilian infrastructure.

An HPM weapon has a shorter possible range than HEMP, but it can induce currents large enough

to melt circuitry, or it can cause equipment to gradually fail over a period of minutes, days, or

even weeks. In 2001, a U.S. Comanche helicopter, flying in New York while performing a radar

test involving HPM weapons, generated a low-level energy pulse that reportedly disrupted for

two weeks the global positioning systems (GPS) being used to land commercial aircraft at a

nearby airport in Albany, New York.24

A HEMP attack directed against the Unites States continent might involve a one-megaton nuclear

warhead, or a smaller one, using a burst several hundred miles above the mid-western states to

affect computers on both coasts.25 However, creating a HEMP effect over an area 250 miles in

diameter, an example size for a battlefield, might only require a rocket with a modest altitude and

payload capability that could loft a relatively small nuclear device. If a medium or higher range

missile with a nuclear payload were launched from the deck of a freighter at sea, the resulting

HEMP could reportedly disable computers over a wide area of the coastal United States.

The disruptive effects of both HEMP and HPM reportedly diminish with distance, and electronic

equipment that is turned off is only less likely to be damaged. 26 To produce maximum coverage

for the HEMP effect, a nuclear device must explode very high in the atmosphere, too far away

from the earth’s surface to cause injury or damage directly from heat or blast. Also, HEMP

produced by the nuclear explosion is instantaneous—too brief to start current flowing within a

human body—so there is no effect on people. However, microwave energy weapons (HPM) are

smaller-scale, are delivered at a closer range to the intended target, and can sometimes be emitted

for a long duration. These characteristics of HPM can sometimes cause a painful burning

sensation or other injury to a person directly in the path of the focused power beam, or can even

be fatal if a person is too close to the microwave emitter.27

William Graham, Electromagnetic Pulse Threats to U.S. Military and Civilian Infrastructure, hearing before the

Military Research and Development Subcommittee, House Armed Services Committee, October 7, 1999; and Carlo

Kopp, “The Electromagnetic Bomb—A Weapon of Electrical Mass Destruction,” Air and Space Power.

Kenneth R. Timmerman, “U.S. Threatened with EMP Attack,” Insight on the News, May 28, 2001.

http://www.physics.northwestern.edu/classes/2001Fall/Phyx135-2/19/emp.htm.

Experts may disagree on whether the damaging effects of HPM actually diminish following the familiar inversesquare-of-the-distance rule. Michael Abrams, “The Dawn of the E-Bomb,” IEEE Spectrum, November 2003,

http://www.spectrum.ieee.org/WEBONLY/publicfeature/nov03/1103ebom.html. Some experts state that the severity of

HEMP effect depends largely on the bomb design, so a specially-designed low yield bomb may pose a larger HEMP

threat than a high yield bomb. Lowell Wood, statement before the House Research and Development Subcommittee,

hearing on EMP Threats to the U.S. Military and Civilian Infrastructure, October 7, 1999.

Victorino Matus, “Dropping the E-bomb,” The Weekly Standard, February 2, 2003, http://theweeklystandard.com/

(continued...)

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Both HEMP and HPM can permanently immobilize vehicles with modern electronic ignition and

control systems. However, older electrical components, such as vacuum tubes and induction coils

for spark ignition, are generally built more massively, and are more tolerant of EMP. As modern

electronics shrink in size, circuitry is becoming increasingly tiny and more vulnerable to

electromagnetic interference. Therefore, countries with infrastructure that relies on older

technology may be less vulnerable to the disabling effects of HEMP or HPM than countries that

rely on a higher level of technology. 28

Recovery After Attack

The simultaneous loss of communications and power that would likely result from an EMP attack

would also complicate the restoration of systems. Without communications, it would be difficult

to ascertain the nature and location of damage, or to order personnel out to make repairs. The

estimated recovery times for various elements of the electrical system are provided in a list that

appears on pages 50-51 of the 2008 Commission report.

The report states that the continuing business need to improve and expand the electric power

system provides an opportunity to improve both the security and reliability of the entire system in

an economically acceptable manner.29 The Commission reported that the seriousness of loss of

the electric power grid could be reduced through focused coordination between industry and

government. The Commission recommended that the federal government, according to standards

it determines, should validate proposed enhancements to protect systems against damage from

EMP attack, and fund those security related elements.

Economic Damage Estimates after Attack on Washington, D.C.,

Region

In September 2007, the Sage Policy Group of Baltimore and Instant Access Networks (IAN)

published a study of the potential economic impact of a HEMP attack on the BaltimoreWashington-Richmond area. The study focuses on the economic effects of EMP experienced by a

region after a high-altitude EMP pulse generated by a nuclear device detonated between 30-80

miles above ground impacting an area at least 500 miles in radius. In these instances of highaltitude EMP, no one would feel the heat or blast but merely experience the effects of the

disruption or damage to the electronic and power infrastructure. The Baltimore-WashingtonRichmond area likely comprises only one-tenth of the economic loss that would occur for the

total geographic area affected by a regional EMP event.

The report was presents a range of low, medium, and high estimates of economic damage, all

within bounds accepted by a broad range of EMP experts. The methodology relied on

assumptions about disruption and damage to the regional electrical power system,

(...continued)

Utilities/printer_preview.asp?idArticle=2209&R=9F0C225C3.

Lowell Wood, statement before the House Research and Development Subcommittee, hearing on.EMP Threats to the

U.S. Military and Civilian Infrastructure, October 7, 1999.

Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack;

Critical National Infrastructures, April 2008, p. 52.

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communications systems, system control and data acquisition (SCADA) devices, and other

critical infrastructure that might occur as a result of an EMP, and on the time required to repair

that damage and fully restore economic activity. These assumptions were used in combination to

estimate the ultimate effects of an EMP on the region’s economy. The cumulative effect of an

EMP on critical infrastructure was assumed to be largely determined by effects on the electrical

grid and communications systems. Cumulative damage was then determined by multiplying the

remaining capacity of the electrical grid by the remaining capacity of communication systems

under three scenarios. For example, under the high case, an EMP damages 50% of the capacity of

the electric grid and 50% of the capacity of communication systems. The analysis assumed that

the economy was then able to operate at only 25% of capacity (i.e., 50% multiplied by 50%).

The study concluded that an EMP attack affecting the Baltimore-Washington-Richmond region

could result in economic output loss potentially exceeding $770 billion, or 7% of the nation’s

annual gross domestic product. Even under the most favorable assumptions, including both

shielded and unshielded critical infrastructure, an EMP might still result in damage that would

require one month of recovery and economic loss of $9 billion and $34 billion respectively.

Table 1. Estimates of Damage and Recovery Times After HEMP Attack on

Washington, D.C., Regional Area

Percentage of Capacity Damaged

Midpoint of Replacement Times (months)

Low Case

Mid Case

High Case

Low Case

Mid Case

High Case

Transformers

10%

40%

70%

2.5

13.5

33.0

Other

30%

40%

50%

1.5

5.0

10.0

Large

10%

20%

50%

4.0

18.0

27.0

Small

20%

50%

2.0

12.0

17.0

20%

50%

1.5

5.0

10.0

Large

20%

45%

70%

4.0

12.0

17.0

Small

1.5

5.0

10.0

Infrastructure

Electric grid

Communications systems

SCADA

All types

Electronics

Source: Instant Access Networks and Sage Policy Group, “Initial Economic Assessment of

Electromagnetic Pulse (EMP) Impact upon the Baltimore-Washington-Richmond Region,”

September 10, 2007, Exhibit 2, p. 5, at http://www.pti.org/docs-safety/EMPecon_9-07.pdf.

In the worst case, according to the study, not only is the damage from EMP widespread, but the

duration of disrepair lasts for years. In such cases, there are numerous complicating factors that

could slow the recovery process. The quantity of replacement equipment needed to restore the

economy may quickly exhaust readily available supplies and, in extreme cases, existing

manufacturing capacity. In such cases, the availability of skilled labor to replace and restore key

infrastructure elements may also be in extraordinarily short supply. High-altitude EMP would also

affect much larger parts of the region than the immediate Baltimore-Washington-Richmond area,

further complicating recovery efforts. It is unlikely that restoration would occur in an orderly,

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linear fashion. More likely, restoration efforts would start slowly and gather speed as basic

infrastructure is gradually brought on line.

Portable Data Centers and Hardening Against EMP

Electronic equipment may be made more resistant to EMP by surrounding it with protective

metallic shielding, which routes damaging electromagnetic surges away from highly sensitive

electrical components. This method, commonly known as Faraday cage protection, is often used

to protect electronic equipment from a lightning strike. However, these devices must be

constructed carefully. Any wires running into the protected area could act as antennae and

conduct the electromagnetic shockwave into the equipment. These points of entry into a shielded

area must be protected from EMP by using specially designed surge protectors, special wire

termination procedures, screened isolated transformers, spark gaps, or other types of specially

designed electrical filters.30 Additionally, an EMP surge from a very powerful nuclear blast,

possibly involving a 200 Kilovolts/meter electric field, could pass through some protective

shielding.31

Microsoft, Sun Microsystems, and other vendors have recently marketed a new product

commonly called a “Portable Data Center” (PDC) where computer equipment is placed on racks

that are pre-grouped inside a modular room, which can be moved and connected to other portable

computer room modules, as needed. 32 For example, a portable module can hold as many as 1,200

servers along with power supply and a cooling system. All this computer equipment fits into a

box that can be placed inside a 40-foot standard freight shipping container, which can also be

mounted on a truck for portability. 33 This new method for housing computers is intended to

reduce the cost for computer facility installation.

However, additional features may also transform a PDC into an effective method for making U.S.

computer equipment less vulnerable to EMP attack. For example, Instant Access Networks (IAN),

a specialized technology vendor, now offers a portable modular equipment room that reportedly

can meet military specifications for EMP protection. 34 The IAN product uses welded metal

enclosures of precise composition and thickness. A recently filed patent application involves a

unique construction method to block different EMP frequencies and also reduce weight for easier

Electrical systems connected to any wire or line that can act as an antenna may be disrupted. Army Training Manual

5-692-2, April 15, 2001, “Maintenance of Mechanical and Electrical Equipment at Command, Control,

Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities, HEMP Protection

Systems, Chapter 27.

Recent Russian military writings claim that they have a Super-EMP weapon that can generate more than 200 KVs

per meter, which is 4 times greater than the level of EMP hardening tested by the United States. Kilovolts per meter is

the standard measure for describing the strength of an EMP field. In layman’s terms, the statement that a Russian

Super-EMP weapon could generate 200 kilovolts per meter means that a conductive object exposed to the EMP field

will experience a surge of 200,000 volts for every meter of its length. So if the object is 2 meters long, it gets 400,000

volts. If 3 meters long, it gets 600,000 volts, and so on. Testimony from the EMP Commission before the House Armed

Services Committee, Jul 10, 2008.

Rich Miller, Microsoft Mulling Portable Data Centers, http://www.datacenterknowledge.com/archives/2007/April/

05/microsoft_mulling_portable_data_centers.html.

Stephen Shankland, Rackable’s portable data center goes on sale, CnetNews.com, March 26, 2007,

http://news.cnet.com/Rackables-portable-data-center-goes-on-sale/2100-1010_3-6170495.html.

Instant Access Networks, LLC, provides a commercial off-the-shelf, portable data center that meets or exceeds

military specifications for EMP protection. http://www.safe9-1-1.com/.

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portability. This type of portable module, built and tested according to strict specifications, could

possibly be mass-produced and deployed as an effective way to protect existing and future U.S.

computer systems from EMP attack.35 For example, a single module placed at a remote critical

location could possibly operate as an EMP-protected SCADA system, or multiple shielded

modules could be connected together at a central headquarters location for a high-capacity

protected computing.

DOD has also published Mil-Standard 188-125, which describes methods for protecting against

High-Altitude Electromagnetic Pulse for ground-based command and control facilities.36

However, not all military systems are currently hardened against EMP. In addition, some DOD

systems rely on commercial facilities, such as communications satellites and ground-based

stations, for support of military operations. Hardening most military systems, and mass-produced

commercial equipment including PCs and communications equipment, against HEMP or HPM

reportedly would add from 2% to 3% to the total cost, if the hardening is engineered into the

original design. To retro-fit existing military electrical equipment with hardening would add about

3%-10% to the total cost.37

DOD Vulnerabilities and Research

In 2004, the EMP Commission held the collective the opinion that DOD had not engaged in any

tabletop exercises and simulations that anticipate and EMP attack. In fact, an EMP commissioner

observed that over the past 40 years, DOD has tended to “not introduce EMP attack into exercise

scenarios or game scenarios because it tends to end the game, and that is not a good sign.”38

In April, 2005, the Defense Science Board (DSB) Task Force on Nuclear Weapon Effects (NWE)

Test, Evaluation and Simulation published a report for DOD describing current and emerging

threat environments. This included a comprehensive evaluation of future DOD capabilities for

successful operation in nuclear environments. The DSB findings were independent, “but are

highly consistent with, the findings and recommendations of the Congressionally mandated

Electromagnetic Pulse (EMP) Commission.” The DSB findings include the following:

Despite the reduction of the threat of strategic nuclear exchange, it is becoming more, not

less, likely that U.S. forces will have to operate in a nuclear environment in regional

operations. This is driven by the proliferation of nuclear weapon capabilities and the

attractiveness of nuclear weapons as an offset to U.S. conventional superiority and as a

counter to U.S. preemptive doctrine.... factors that should make decision makers concerned

about the survivability of critical warfighting elements in a nuclear environment. These

include the shift to commercial-off-the-shelf (COTS) based electronics, aging of key

systems, the growing reliance on historically “soft” C4ISR2 assets, the general neglect of

nuclear hardening as a requirement, and the general neglect of nuclear environments as a

Charles Manto, et al., Pending U.S. Patent number 20070105445, “System and Method for Providing Certifiable

Electromagnetic Pulse and RFI Protection Through Mass-Produced Shielded Containers and Rooms”, published May

10, 2007.

MIL-STD-188-125-1, April 2005, http://www.wbdg.org/ccb/FEDMIL/std188_125_1.pdf.

Lowell Wood, statement before the House Research and Development Subcommittee, hearing on EMP Threats to the

U.S. Military and Civilian Infrastructure, October 7, 1999. Personal communication with EMP Commission members,

July 2008.

Dr. Lowell Wood, testimony before the House Committee on Armed Services, H.A.S.C No. 108-37, July 22, 2004,

p. 23.

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factor in gaming and exercises. The bottom line is that commanders and planners cannot be

assured that today’s weapons platforms, command and control (C2), intelligence,

surveillance and reconnaissance (ISR), and associated support systems will be available

should a nuclear detonation occur.39

Underground testing of nuclear devices done in 1992 at the Nevada Test Site were designed to

research protection techniques to harden military systems against HEMP effects resulting from a

nuclear exchange. 40 The Limited Test Ban Treaty of 1963 prohibits nuclear explosions in the

atmosphere, in space, and under water. Since then, testing to calibrate the effects of large-scale

HEMP on the critical infrastructure has been restricted. The design of new simulators to help

measure these effects would call for complex computations to represent the large number of

possible interactions between components found in the circuit boards, network connections,

wireless systems, hardware modules, and operating environments of modern electronic systems

that support the critical infrastructure.

DOD research on pulsed-power HPM electromagnetic weapons is currently being done at

Kirtland Air Force Base, in Albuquerque, New Mexico. Weapons now being developed by the

U.S. military for electronic warfare can disrupt the trajectory of missiles while in flight, and can

overpower or degrade enemy communications, telemetry, and circuitry. Other HPM weapons

being tested by the military are portable and re-usable through battery-power, and many are

effective when fired miles away from a target. These weapons can also be focused like a laser

beam and tuned to an appropriate frequency in order to penetrate electronics that are heavily

shielded against a nuclear attack. The deepest bunkers with the thickest concrete walls reportedly

are not safe from such a beam if they have even a single unprotected wire reaching the surface. 41

Because instantaneous HPM energy can reflect off the ground and possibly affect piloted aircraft

above, much testing currently involves HPM devices on Unmanned Aerial Vehicles (UAVs), and

on the Air Force Conventional Air-Launched Cruise Missile system. By 2010, DOD reportedly

will field several air-launched UAVs using disposable and reusable HPM weapons designed to

disrupt enemy computers.42

Ground Wave Emergency Network

During the Cold War, the US Military designed an innovative communications system to relay

emergency messages between strategic military areas in the continental United States, using

signals that travel by means of low frequency ground waves—electromagnetic fields that hug the

ground—rather than by radiating into the atmosphere. The Ground Wave Emergency Network, or

GWEN system, was intended to allow continuous communications despite EMP disruptions.

However, the hardware was reportedly transistor based, leaving the system with some level of

Report of the Defense Science Board Task Force on Nuclear Weapon Effects Test, Evaluation, and Simulation, April

2005, at http://www.acq.osd.mil/dsb/reports/2005-04-NWE_Report%20_Final.pdf.

Associated Press, “Experts Cite Electromagnetic Pulse as Terrorist Threat,” Las Vegas Review-Journal, October 3,

2001.

Michael Abrams, The Dawn of the E-Bomb, IEEE Spectrum Online, November 2003, http://www.spectrum.ieee.org/

WEBONLY/publicfeature/nov03/1103ebom.html.

David Fulghum and Douglas Barrie Farnboruogh, “Directed-Energy Weapon for UAV, cruise and air-to-ground

missile payloads nears production,” Aviation Week & Space Technology, July 26, 2004, p. 34.

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vulnerability to EMP. In addition, the fixed locations of GWEN sites were known to adversaries,

and thus vulnerable to direct attack.43

As the Cold War ended, the U.S. military took steps to reduce its nuclear arsenal and associated

infrastructure.44 After 1998, the USAF decommissioned GWEN assets and replaced the entire

system with the Single Channel Anti-Jam Man-Portable (SCAMP) Terminal. SCAMP uses

extremely high frequency (EHF) technology, is resistant to EMP, and offers more flexibility than

GWEN because the equipment is lightweight, transportable, and interoperable with DOD satellite

networks.45

EMP Capabilities of Other Nations

Reportedly, several potential U.S. adversaries, such as Russia or China, are now capable of

launching a crippling HEMP strike against the United States with a nuclear-tipped ballistic

missile, and other nations, such as North Korea, could possibly have the capability by 2015.46

Other nations that could possibly develop a capability for HEMP operations over the next few

years include United Kingdom, France, India, Israel, and Pakistan.

In 2005, Iran reportedly acquired several medium and intermediate-range ballistic missiles from

North Korea, with a range of 2,500 miles.47 In 2006, Iran tested several of their Shahab-3 nuclearwarhead-capable ballistic missiles, which were exploded in mid-flight. While these explosions

could have been the result of a missile self-destruct mechanism, Iran has officially described the

tests in 2006 as fully successful. It was noted by witnesses at a 2005 hearing of the Senate

Committee on the Judiciary, Subcommittee on Terrorism, Technology and Homeland Security,

that this event could indicate that Iran may be practicing for the execution of an HEMP attack.48

In July 2008, Iran test-launched several more long-range ballistic missiles. However, other

observers caution that these and similar actions might simply be a scare tactic used by Iran, but

without much substance.49

Rosalie Bertell, “Background on the HAARP Project,” Global Policy Forum, November 5, 1996,

http://www.globalpolicy.org/socecon/envronmt/weapons.htm.

Admiral Richard W. Mies, Commander in Chief, United States Strategic Command, statement before the Senate

Armed Services Committee Strategic Subcommittee on Command Posture, July 11, 2001, p.11,

http://www.defenselink.mil/dodgc/lrs/docs/test01-07-11Mies.rtf.

Federation of American Scientists, AN/PSC-11 Single Channel Anti-Jam Man-Portable (SCAMP)Terminal, March

2000 http://www.fas.org/spp/military/program/com/an-psc-11.htm.

Michael Sirak, “U.S. vulnerable to EMP Attack,” Jane’s Defence Weekly, July 26, 2004, http://www.janes.com/

defence/news/jdw/jdw040726_1_n.shtml, and House Armed Services Committee, hearing on Commission to Assess the

Threat to the United States from Electromagnetic Pulse Attack, July 22, 2004.

Alon Ben-David, Iran Acquires Ballistic Missiles from DPRK, Jane’s Intelligence and Oversight, December 29,

2005.

Senate Committee on the Judiciary, Subcommittee on Terrorism, Technology and Homeland Security, March 8,

2005. Jane’s Information Group, Shahab break-ups suggest possible EMP trial , May 1, 2005, Jane’s Rockets and

Missiles. Joseph Farah, Iran plans to knock out U.S. with 1 nuclear bomb, April 25, 2005, WorldNewsDaily.com,

http://wnd.com/news/article.asp?ARTICLE_ID=43956.

Officials in Iran have also reported that in March 2006, they successfully tested their “Fajr-3” long-range missile,

which they claim has a range of 2000 miles, and which is invisible to radar. However, other intelligence sources

reportedly argue that the “Fajr-3” is merely an upgraded artillery shell with a very short range. “Iran Claims Test of

Fajr-3 Missile ‘Invisible’ to Radar, Interceptors,” April 3, 2006, MissileThreat.com, http://www.missilethreat.com/

news/200604030826.html.

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A discussion of asymmetric warfare and anti-satellite weapons, at a June 25, 2008, hearing by the

House Armed Services Committee, included the possible example of the United States being

targeted for attack by China using EMP.50 According to a 1999 DOD report, China has been

actively pursuing the development of electromagnetic pulse weapons, and has devoted significant

resources to development of other electronic warfare systems and laser weapons. The report also

noted that China’s leaders view offensive counter space weapons and other space-based defense

systems as part of inevitable scenarios for future warfare. The report noted that China could have

as many as 60 ICBMs capable of striking the United States by 2010. Also, China may replace 20

of its current ICBMs with a longer-range missile by the end of this decade, or sooner.51

Vladimir Lukin, the former Soviet Ambassador to the United States, and former Chairman of the

International Affairs Committee for the Russian Parliament, reportedly has stated that Russia

currently has a capability to create a HEMP effect over the United States.52 During 1962, the then

Soviet Union conducted a series of atmospheric nuclear tests and observed HEMP effects that

included surge protector burnouts, power supply breakdowns, and damage to overhead and

underground buried cables at distances of 600 kilometers. Since then, Russia has reportedly made

extensive preparations to protect their infrastructure against HEMP by hardening both civilian

and military electronic equipment, and by providing continuous training for personnel operating

these protected systems.53 Other sources have reportedly stated that Russia may also have some of

the leading physicists in the world currently doing research on electronic warfare weapons and

electromagnetic pulse effects.54

Policy Analysis

Preparedness

What is the United States doing to protect critical infrastructure systems against the threat of

electromagnetic pulse? What is the appropriate response from the United States to a nuclear

HEMP attack, where there may be widespread damage to electronics, but relatively little, or

possibly no loss of life as a direct result? How could the United States determine which nation or

group launched a HEMP attack? After experiencing a HEMP effect, the United States may retain

its capability to use strategic weapons for nuclear retaliation, but will the U.S. industrial base and

critical infrastructure be crippled or incapable of supporting a sustained military campaign?

Testimony of James Shinn, Assistant Secretary of Defense, Security Developments in China, hearing before the

House Armed Services Committee, June 25, 2008.

FY04 Report to Congress on PRC Military Power, Annual Report on The Military Power of the People’s Republic of

China, http://www.defenselink.mil/pubs/d20040528PRC.pdf.

The statement was reportedly made on April 30, 1999, to a U.S. Congressional delegation that traveled to Vienna to

meet with officials from the Russian Duma to discuss a framework for a peaceful solution of the then crisis in Kosovo.

Hearing before the Military Research and Development Subcommittee of the Committee on Armed Services House of

Representatives, October 7, 1999, http://commdocs.house.gov/committees/security/has280010.000/has280010_0.HTM.

Lowell Wood, statement before the House Research and Development Subcommittee, hearing on EMP Threats to the

U.S. Military and Civilian Infrastructure, October 7, 1999.

Barry Crane, a physicist and former F-4 pilot now working at the Institute for Defense Analysis, has visited Russia’s

top electromagnetic pulse laboratories and design bureaus, and has stated that many Russian electromagnetic pulse

specialists may also be now working on contract in China. Kenneth R. Timmerman, May 28, 2001, “U.S. Threatened

with EMP Attack,” Insight on the News.

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During such time, would the United States be capable of a making an effective response should

other nations chose to make military advances in other parts of the world?

A large percentage of U.S. military communications during Operation Iraqi Freedom was

reportedly carried over commercial satellites, and much military administrative information is

currently routed through equipment that comprises the civilian Internet. 55 Many commercial

communications satellites, particularly those in low earth orbit, reportedly may degrade or cease

to function shortly after a high altitude nuclear explosion.56 Many commercial satellite control

stations on the ground may also degrade after an EMP attack. However, some observers believe

that possible HEMP and HPM vulnerabilities of military information systems are outweighed by

the benefits gained through access to innovative technology and increased communications

flexibility that come from using state-of-the-art electronics and from maintaining connections to

the civilian Internet and satellite systems.

The effects of large-scale HEMP have been studied over several years by the Defense Atomic

Support Agency, the Defense Nuclear Agency, and the Defense Special Weapons Agency, and are

currently being studied by the Defense Threat Reduction Agency (DTRA). However, the

application of the results of these studies has been uneven across military weapons and

communications systems. Some analysts argue that U.S. strategic military systems

(intercontinental ballistic missiles and long-range bombers) may have strong protection against

HEMP, while many other U.S. weapons systems used for the battlefield have less protection, and

that this is undoubtedly known to our potential adversaries.57

Some analysts reportedly state that limited testing has shown modern commercial equipment may

be surprisingly resistant to the effects of electromagnetic pulse, and some military systems using

commercial equipment have been retrofitted to increase resistance to EMP.58 However, there is

disagreement among observers about whether the procedures used by the U.S. military to test

EMP survivability may have been flawed, leading to erroneous conclusions about the effects of

electromagnetic pulse on commercial electronics.59

Department of Homeland Security

As part of its risk analysis mission, the Department of Homeland Security (DHS) has developed a

set of 15 National Planning Scenarios, which depict a diverse set of high-consequence threat

Jefferson Morris, “DISA Chief Outlines Wartime Successes,” Federal Computer Week, June 6, 2003; and “GAO:

DOD Needs New Approach to Buying Bandwidth,” Aerospace Daily, December 12, 2003.

U.S. Congress, House Armed Services Committee, Hearing on Commission to Assess the Threat to the United States

from Electromagnetic Pulse Attack, July 22, 2004.

Because of the very specialized nature, strategic weapons use essentially no commercial equipment. However, DOD

increasingly uses commercial equipment in other tactical weapons. Stanley Jakubiak and Lowell Wood, statements

before the House Military Research and Development Subcommittee, hearing on EMP Threats to the U.S. Military and

Civilian Infrastructure, October 7, 1999.

Stanley Jakubiak, statement before the House Military Research and Development Subcommittee, Hearing on EMP

Threats to the U.S. Military and Civilian Infrastructure, October 7, 1999.

Lowell Wood, statement before the House Military Research and Development Subcommittee, hearing on EMP

Threats to the U.S. Military and Civilian Infrastructure, October 7, 1999; and Jack Spencer, “America’s Vulnerability

to a Different Nuclear Threat: An Electromagnetic Pulse,” The Heritage Foundation Backgrounder, No.1372, May 26,

2000, p.6.; and Carlo Kopp, “The Electromagnetic Bomb—A Weapon of Electrical Mass Destruction,” Air and Space

Power 1993.

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scenarios of both potential terrorist attacks and natural disasters. These 15 scenarios are designed

to focus contingency planning for homeland security preparedness work, at all levels of

government, and with the private sector. These scenarios form the basis for coordinated federal

planning, training, exercises, and grant investments needed to prepare for emergencies of all

types.60 However, EMP Commission members stated at the 2008 HASC hearing that they have

been unable to convince DHS to add EMP attack to its list of National Planning Scenarios.61

Nuclear Incentive

A single nuclear device exploded at an appropriate altitude above the continental United States

could possibly affect our industrial capacity, economic stability, and military effectiveness. Does

knowledge of this vulnerability, combined with the proliferation of nuclear technology, provide a

new incentive for potential adversaries to develop or acquire a nuclear weapons capability? Will

countries now view the development and acquisition of nuclear weapons, even a small arsenal, as

a strategy for cyber warfare?

During the Cold War, a HEMP attack was viewed as the first step of a nuclear exchange involving

many warheads, but the threat of mutually assured destruction provided a lasting deterrent. Today,

the proliferation of nuclear technology makes the threat of HEMP attack more difficult to assess.

Would the leader of a rogue state be motivated to use a small nuclear arsenal to launch a crippling

HEMP strike against the United States, with no resulting fatalities, if it believed the U.S. likely

would not retaliate with a nuclear salvo, destroying thousands, or millions of innocent people?

Would a HEMP strike over a disputed area during a regional conflict be seen as a way to defeat

the communications links and network centric capability of the U.S. military, and gain battlefield

advantage from an existing supply of smaller nuclear warheads?62

Terrorists

A smaller-scale HPM weapon requires a relatively simple design, and can be built using electrical

materials and chemical explosives that are easy to obtain. It is estimated that a limited-range

suitcase-sized HPM weapon could be constructed for much less than $2,000, and is within the

capability of almost any nation, and perhaps many terrorist organizations. 63 In 2001, DOD

recruited a scientist to create two small HPM weapons for testing using only commercially

available electrical components, such as ordinary spark plugs and coils. One device was

developed that could be broken down into two parcels so it could be shipped by regular mail, for

example, from one terrorist to another. The second HPM device was constructed to fit inside a

small vehicle. 64 Currently, HPM devices, including suitcase-sized devices powerful enough to

Department of Homeland Security, National Preparedness Guidelines, September 2007, Fig. B-1, p.31,

http://www.dhs.gov/xlibrary/assets/National_Preparedness_Guidelines.pdf.

William Graham, testimony before the House Armed Services Committee, July 10, 2008.

Jack Spencer, “America’s Vulnerability to a Different Nuclear Threat: An Electromagnetic Pulse,” The Heritage

Foundation Backgrounder, No.1372, May 26, 2000, p. 3.

Some experts may disagree about whether most terrorist organizations are capable of building an inexpensive HPM

weapon powered by a flux-compression generator. Michael Abrams, “The Dawn of the E-Bomb,” IEEE Spectrum

Online, November 2003, http://www.spectrum.ieee.org/WEBONLY/publicfeature/nov03/1103ebom.html, and Carlo

Kopp, “The Electromagnetic Bomb—A Weapon of Electrical Mass Destruction,” Air and Space Power, 1993.

Kenneth R. Timmerman, “U.S. Threatened with EMP Attack,” Insight on the News, May 28, 2001.

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High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

jam or destroy electronic facilities, are reportedly also available through catalog sales from

commercial vendors.65

It is difficult to assess the threat of a terrorist organization possibly using a smaller-scale HPM

weapon against the United States critical infrastructure. It could be argued that an HPM bomb by

itself, may not be attractive to terrorists, because its smaller explosion would not be violent

enough, and the visible effect would not be as dramatic as a larger, conventional bomb. Observers

have reported that the leadership of some terrorist organizations may increasingly become aware

of the growing advantages from an EMP attack launched against U.S. critical information

systems. In addition, the use of a new weapon directed at U.S. information systems would attract

widespread media attention, and may motivate other rival groups to follow along a new

pathway. 66

Human Rights

HEMP and HPM energy weapons primarily damage electronic systems, with little or no direct

effect on humans, however, these effects may be difficult to limit or control. As HEMP or HPM

energy fields instantly spread outward, they may also affect nearby hospital equipment or

personal medical devices, such as pace-makers, or other parts of the surrounding civilian

infrastructure. For this reason, some international human rights organizations may object to the

development or testing of HEMP or HPM weapons.

Legislative Activity

P.L. 110-181, The National Defense Authorization Act for Fiscal Year 2008, requires the

Department of Homeland Security to coordinate efforts with the Commission for work related to

electromagnetic pulse attack on electricity infrastructure, and protection against such attack.

Funding by provided by the Department of Defense to the Commission for preparation and

submission of the final report is limited to $5,600,000. The deadline for the submission of the

final report of the Commission has been extended to November 30, 2008.

CRS Products

CRS Report RL32114, Botnets, Cybercrime, and Cyberterrorism: Vulnerabilities and Policy

Issues for Congress.

CRS Report RL32411, Network Centric Operations: Background and Oversight Issues for

Congress.

CRS Report RS21528, Terrorist “Dirty Bombs”: A Brief Primer.

Personal communication with EMP Commission. Diehl BGT Defense, High Power Microwaves, http://www.diehlbgt-defence.de/index.php?id=547&L=1.

Jerrold M. Post, Kevin G. Ruby, and Eric D. Shaw, “From Car Bombs to Logic Bombs: The Growing Threat from

Information Terrorism,” Terrorism and Political Violence, vol. 12, no. 2 (summer 2000), pp. 97-122.

Congressional Research Service

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices

CRS Report IB92099. Nuclear Weapons: Comprehensive Test Ban Treaty.

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