Understanding the War Powers Resolution

December 17, 2025

Understanding the War Powers Resolution

Under the Constitution, authority concerning the use of the

military is divided between Congress and the President. In

the wake of the Vietnam War, concern increased in

Congress about presidential use of U.S. Armed Forces

without congressional authorization. On November 7, 1973,

Congress enacted the War Powers Resolution (WPR; P.L.

93-148; 50 U.S.C. Ch. 33) over the veto of President Nixon,

creating a structure for Congress to respond to the

introduction of U.S. Armed Forces into situations that

involve or might lead to hostilities.

For historic information on the WPR, its application, and

related policy issues, see CRS Report R42699, The War

Powers Resolution: Concepts and Practice, by Matthew C.

Weed.

Structure of the War Powers Resolution

The WPR’s provisions, detailed below, operate to provide

Congress with the information and roadmap to make

decisions alongside the President about the use of the

military. Under the WPR, the President is required to

inform and consult with Congress about possible and

current uses of U.S. Armed Forces, and Congress may or

may not act in expedited fashion to authorize or limit

presidential use of the military.

Title (Section 1)

Although the legislation is sometimes referred to as the

“War Powers Act,” Section 1 establishes the title of the

legislation as the War Powers Resolution. Adding to the

possible confusion, measures introduced pursuant to the

expedited consideration procedures in Sections 6 and 7 (see

below) are often termed “war powers resolutions,” but these

measures are separate from the War Powers Resolution

itself. As explained below, the War Powers Resolution

creates a structure and process under which individual war

powers measures are considered.

Purpose, Policy, and Role of Congress (Section 2)

Section 2(a) states that the WPR’s purpose is to “insure that

the collective judgment of both the Congress and the

President will apply to the introduction of United States

Armed Forces into hostilities.” Section 2(b) explains that

Congress’s authority to legislate on war powers emanates

from the Necessary and Proper Clause of the Constitution,

which grants Congress “the power to make all laws

necessary and proper for carrying into execution” the

powers of the federal government, including those of the

executive branch. Section 2(c) states that the powers of the

President as Commander in Chief to introduce U.S. Armed

Forces into hostilities are limited, “exercised only pursuant

to” a declaration of war or other specific statutory

authorization from Congress, or a “national emergency

created by attack on” the United States or its Armed Forces.

Consultation with Congress (Section 3)

Section 3 of the War Powers Resolution requires the

President “in every possible instance” to consult with

Congress before introducing U.S. Armed Forces into

situations of ongoing or imminent hostilities, and to

continue consultations as long as the Armed Forces remain

in such situations.

Notification to Congress (Section 4)

Section 4 is the WPR’s central provision, designed to

ensure that Congress is notified of military deployments

that could involve the exercise of congressional war

powers. Section 4(a)(1) requires the President, in the

absence of a declaration of war, to notify the Speaker and

President Pro Tempore within 48 hours after U.S. Armed

Forces are introduced “into hostilities or into situations

where imminent involvement in hostilities is clearly

indicated by the circumstances.” While “hostilities” is not

defined in the WPR, the House report accompanying the

original measure stated that the term includes not only “a

situation in which fighting actually has begun,” but also “a

state of confrontation in which no shots have been fired but

where there is a clear and present danger of armed

conflict.” The report indicated that “imminent hostilities”

includes “a situation in which there is a clear potential

either for such a state of confrontation or for actual armed

conflict.”

Section 4(a)(2) and (3) require the President to report other

deployments of U.S. Armed Forces “into the territory,

airspace or waters of a foreign nation, while equipped for

combat, except for deployments which relate solely to

supply, replacement, repair, or training of such forces,” or

additional deployments “in numbers which substantially

enlarge United States Armed Forces equipped for combat

already located in a foreign nation.”

All Section 4(a) notifications must include information on

(1) “the circumstances necessitating the introduction of

United States Armed Forces”; (2) “the constitutional and

legislative authority under which such introduction took

place”; and (3) “the estimated scope and duration of the

hostilities or involvement.”

Section 4(c) requires the President to report to Congress

periodically, and at least every six months, on continuing

deployments of U.S. forces reported under Section 4(a).

Congressional Response to an Introduction of U.S.

Armed Forces (Section 5)

Section 5 sets out possible congressional responses to

authorize or terminate an unauthorized presidential use of

the military. Pursuant to Section 5(a), a Section 4 report of

hostilities shall be transferred to both the House Foreign

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Understanding the War Powers Resolution

Affairs and Senate Foreign Relations Committees for

consideration. Section 5(b) states that when the President

reports an introduction of U.S. Armed Forces into active or

imminent hostilities, or such report is required under

Section 4(a)(1) but not made, the President must terminate

such use of U.S. Armed Forces after 60 days unless

Congress (1) has declared war or specifically authorized the

action, (2) has extended the 60-day period by law, or (3) is

physically unable to meet as a result of an armed attack on

the United States. The period of deployment can be

extended an additional 30 days by the President if the

President certifies that “unavoidable military necessity

respecting the safety of United States Armed Forces”

requires their continued use in the course of bringing about

their removal.

Section 5(b) is sometimes interpreted to allow the President

to unilaterally involve U.S. Armed Forces in hostilities for

any reason for at least 60 days. This interpretation might

seem at odds with the assertions of limited presidential war

power in Section 2(c), as well as Section 8(d)(2), which

states that the WPR does not confer any presidential

authority to involve U.S. Armed Forces in hostilities. Under

Section 6 (see below), the 60-day period seems to serve

primarily as a window for Congress to possibly authorize

an otherwise unauthorized use of the military.

Under Section 5(c), Congress may require the President to

remove U.S. Armed Forces from such unauthorized

hostilities at any time by concurrent resolution.

Termination Measures Outside WPR Procedure

After a Supreme Court decision that called into question

whether Section 5(c) of the WPR constituted an

unconstitutional legislative veto, Congress enacted Section

1013 of the Department of State Authorization Act, Fiscal

Years 1984 and 1985 (P.L. 98-164; 50 U.S.C. 1546a), to

provide expedited consideration of a joint resolution or bill,

rather than a concurrent resolution, requiring removal of U.S.

Armed Forces from unauthorized hostilities. This provision

utilizes a 1976 provision for privileged procedure in the

Senate, but not the House. Alongside Section 5(c) concurrent

resolutions, both the Senate and the House have increasingly

considered joint resolutions under this procedure.

Priority Procedure to Cure Unauthorized

Hostilities (Section 6)

Section 6 establishes expedited procedures for

congressional consideration of a joint resolution or bill

introduced to authorize an otherwise unauthorized use of

Armed Forces under Section 5(b). A joint resolution or bill

to authorize is privileged if introduced no later than 30 days

before the end of the 60-day period. Such a measure shall

be referred to the House Foreign Affairs or Senate Foreign

Relations Committee. No later than 24 days before the end

of the period, the committee considering the measure shall

report the measure to its respective chamber, and that

chamber shall vote on the measure within three calendar

days. If adopted, the measure shall be referred to the other

chamber’s committee and reported by that committee to its

respective chamber no later than 14 days before the end of

the period, and that chamber shall likewise vote on the

measure within three calendar days. If the measure is

adopted with differences, a committee of conference shall

be appointed and file its report no later than four days

before the end of the period. If the conferees cannot agree

within 48 hours, they shall report to their respective

chambers, and both chambers shall “act on” such report

before the end of the period.

Priority Procedure to Terminate Unauthorized

Hostilities (Section 7)

Section 7 establishes expedited procedures for

consideration of a concurrent resolution requiring removal

of U.S. Armed Forces from unauthorized hostilities under

Section 5(c). Such a measure shall be referred to the House

Foreign Affairs or Senate Foreign Relations Committee,

and the relevant committee shall report the measure to its

respective chamber within 15 calendar days. That chamber

shall vote on the measure within three calendar days after

receipt from the committee. If adopted, the measure shall be

referred to the other chamber’s committee and reported by

that committee to its respective chamber within 15 calendar

days, with that chamber likewise voting on the measure

within three calendar days thereafter. If the measure is

adopted with differences, a committee of conference shall

be appointed and file its report no later than six days after

referral to it. If the conferees cannot agree within 48 hours,

they shall report such disagreement to their respective

chambers.

Interpretive Provisions (Section 8)

Section 8 contains interpretive provisions. Section 8(a)

states that the authority for hostilities is not to be inferred

from any law or treaty, unless such law or treatyimplementing legislation specifically authorizes hostilities

and states that it is “intended to constitute specific statutory

authorization within the meaning of this joint resolution.”

Section 8(b) allows U.S. personnel to participate in the

“headquarters operations” of multilateral “high-level

military commands,” such as the North Atlantic Treaty

Organization (NATO) and the North American Air Defense

Command (NORAD), without specific authorization.

Section 8(c) defines “introduction of United States Armed

Forces” to include the assignment of U.S. forces to

“command, coordinate, participate in the movement of, or

accompany” regular or irregular military forces of other

countries when engaged, or potentially engaged, in

hostilities.

Section 8(d) states that nothing in the WPR is intended to

alter the constitutional authority of either the Congress or

the President. It also specifies that nothing is to be

construed as granting any authority to introduce troops that

would not exist in the absence of the WPR.

Separability Clause (Section 9)

Section 9 is a separability clause, stating that if any

provision or its application is found invalid, the remainder

of the WPR is not to be affected.

Matthew C. Weed, Specialist in Foreign Policy Legislation

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Understanding the War Powers Resolution

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