What Is the War Powers Resolution: The 48-Hour Report and 60-Day Clock

The War Powers Resolution is a 1973 federal law that limits the president’s ability to send U.S. forces into combat without congressional approval. It requires the president to notify Congress within 48 hours of introducing troops into hostilities and to pull those forces out within 60 days unless Congress authorizes the mission to continue. Congress passed it over President Richard Nixon’s veto on November 7, 1973, after years of frustration with executive war-making during Vietnam.¹

Why Congress Passed It

The Constitution divides war powers. Article I gives Congress the power to declare war. Article II makes the president commander in chief. For most of American history that tension was workable, but Vietnam broke the pattern. Presidents ran a massive military commitment in Southeast Asia for more than a decade without ever getting a formal declaration of war, and Congress felt cut out of the most consequential decision a government makes.

The law’s stated purpose is to ensure that the “collective judgment of both the Congress and the President” governs when the country enters hostilities.¹ Nixon vetoed the bill as an unconstitutional restriction on presidential power. Congress overrode him. Every president since has echoed some version of Nixon’s objection, and that ongoing disagreement shapes how the law works in practice.

The 48-Hour Report

Before sending forces into actual or likely combat, the president is supposed to consult with Congress “in every possible instance,” and that obligation continues as long as forces remain engaged.¹ In practice, “consultation” has often meant a phone call to congressional leaders shortly before or after strikes begin.

The reporting requirement is more concrete. Within 48 hours of a covered deployment, the president must send a written report to the Speaker of the House and the President pro tempore of the Senate explaining why the deployment was necessary, the constitutional and legal authority behind it, and how long it is expected to last.²

Three kinds of deployments trigger the report:

Sending forces into hostilities or situations where combat is imminent
Deploying combat-equipped forces into another country’s territory
Substantially enlarging combat-ready forces already in a foreign nation

Once troops are engaged, follow-up reports are due at least every six months.²

The 60-Day Clock

The teeth of the law are in the 60-day clock. Once the president submits a hostilities report, or should have submitted one, a countdown begins. If Congress does not authorize the operation within 60 days, the president must start withdrawing forces.³

The clock stops only if Congress declares war, enacts a specific authorization for the use of force, extends the 60-day window by passing a new law, or is physically unable to meet because of an armed attack on the United States. Without one of those actions, the legal authority to keep troops in the field expires.³

The president can add up to 30 more days, but only by certifying in writing that troop safety requires continued operations specifically to complete a withdrawal. That extension is meant to protect forces during a pullout, not to continue the mission. With it, the outer limit for unauthorized action is 90 days.³

How Congress Can End a Deployment Sooner

Congress does not have to wait out the clock. The Resolution lets Congress direct the president to withdraw forces at any time by passing a concurrent resolution, as long as those forces are engaged in hostilities abroad without a declaration of war or specific statutory authorization. The law also sets fast-track procedures so that leadership in either chamber cannot bury a withdrawal measure in committee.³

There is a serious catch. In 1983, the Supreme Court ruled in INS v. Chadha that legislative actions with the force of law must pass both chambers and go to the president for signature or veto. A concurrent resolution skips that last step; it never reaches the president’s desk.⁴ That makes the concurrent-resolution withdrawal mechanism constitutionally suspect, since ordering troops home is exactly the kind of legally consequential act Chadha says needs presentment. Most analysts think the rest of the Resolution survives even if this piece falls, thanks to a separability clause. The practical effect, though, is that Congress’s most direct override tool likely now requires a joint resolution and, if the president vetoes it, the same two-thirds majority needed to override any veto.

What “Hostilities” Means

The Resolution casts a wide net. It applies not only when U.S. troops enter a combat zone but also when American personnel are assigned to command, coordinate, or accompany the forces of another country that are engaged in or facing imminent hostilities.⁵ The point was to stop a president from putting Americans in harm’s way by embedding them with foreign militaries while claiming the U.S. is not really in the fight.

What the statute never defines is the word “hostilities” itself, and that gap has become the single most contested piece of the whole law. The term clearly covers a ground war. It is vague enough that presidents have argued airstrikes, drone campaigns, and other limited operations fall outside its reach. Whether a particular action counts as “hostilities” is a live fight every time a new operation starts.

How an AUMF Changes Things

The 60-day clock runs only when Congress has not given specific statutory authorization for the operation. An Authorization for Use of Military Force, or AUMF, is exactly that kind of authorization. When Congress passes one, it satisfies the Resolution’s requirement for legislative approval, and the clock either never starts or stops.

The 2001 AUMF, passed days after September 11, spells out the connection. Its text says it “is intended to constitute specific statutory authorization within the meaning of” the War Powers Resolution and that “nothing in this resolution supercedes any requirement of the War Powers Resolution.”⁶ The AUMF gives the president legal cover under the Resolution’s framework while keeping the consultation, reporting, and scope rules intact on paper.

That 2001 AUMF has since been used to justify operations across more than 20 countries over two decades, far beyond what most members of Congress had in mind when they voted for it. It shows a practical weakness in the framework: once Congress provides statutory authorization, the 60-day clock stops constraining anything, and the authorization can sit on the books for years without anyone revisiting whether the original justification still fits.

Why the Law Rarely Forces a Withdrawal

On paper the Resolution looks like a strong check. In practice it has never forced a president to bring troops home. Every president since Nixon has questioned its constitutionality. Executive branch lawyers argue the 60-day clock unconstitutionally restricts the commander in chief, that congressional silence should not automatically end a military operation, and that a public deadline signals weakness to adversaries.

Presidents Avoid Starting the Clock

The simplest workaround is to avoid filing the specific kind of report that starts the countdown. The clock begins only when the president reports, or should report, under the hostilities provision. Presidents routinely send reports that reference the War Powers Resolution in general terms while carefully avoiding the language that would start the 60 days.

Because “hostilities” is undefined, presidents have room to argue. In 2011, the Obama administration said U.S. military operations in Libya, which included extensive airstrikes, did not amount to “hostilities” because American forces faced limited exposure, no ground troops were involved, and the risk of escalation was low.⁷ The argument drew heavy criticism from legal scholars and members of Congress in both parties, but operations continued past the 60-day mark without authorization.

Courts Stay Out

Members of Congress have gone to court at least eight times to try to force compliance. In nearly every case, judges have refused to rule on the merits, citing the political question doctrine, finding legislators lacked standing, or concluding the dispute was not ripe. The judicial posture treats war powers as something the political branches need to sort out themselves, which leaves Congress with no way to compel compliance except its own political will.

The Enforcement Gap

The core problem is structural. The 60-day clock depends on the president filing the right kind of report. The concurrent resolution withdrawal mechanism was weakened by Chadha. Courts will not step in. And Congress is often reluctant to force the issue, because voting to cut off a military operation while troops are already deployed carries heavy political risk. The Resolution ends up functioning more as a framework for negotiation between the branches than as a self-executing rule. When a president is determined to act and Congress is unwilling to use its strongest tool, cutting off funding, the 60-day clock becomes a political benchmark more than a legal deadline.

1
Office of the Law Revision Counsel. 50 USC Chapter 33 – War Powers Resolution
2
Office of the Law Revision Counsel. 50 USC 1543 – Reporting Requirement
3
Office of the Law Revision Counsel. 50 USC 1544 – Congressional Action
4
Justia. INS v. Chadha, 462 U.S. 919
5
Office of the Law Revision Counsel. 50 USC 1547 – Interpretation of Joint Resolution
6
Congress.gov. Public Law 107-40 – Authorization for Use of Military Force
7
U.S. Department of State. Libya and War Powers