What Is the War Powers Act? The 1973 Law Behind the Iran War Votes

It sets three duties for any president who sends U.S. forces into hostilities without a declaration of war or a specific authorization from Congress: consult, report and stop. The president is to consult Congress “in every possible instance” before committing troops. Within 48 hours, the president must send a written report to the Speaker of the House and the president pro tempore of the Senate explaining why forces were sent, under what legal authority, and how large and how long the operation is expected to be.

The report starts a 60-day clock. When it runs out, the president must end the use of force unless Congress has declared war, passed a specific authorization or extended the deadline. The president can add 30 days by certifying in writing that the time is needed to bring the troops out safely. The law also said Congress could order a withdrawal at any time with a concurrent resolution, a measure that never goes to the president for signature.

Congress passed it after Vietnam to claw back its share of the decision to go to war. The Constitution gives Congress the power to declare war and makes the president commander in chief, and through the 1960s presidents widened the Vietnam war without a declaration, including the secret bombing of Cambodia that began in 1969.

President Richard Nixon vetoed the bill on October 24, 1973, calling its restrictions unconstitutional. Congress overrode him on November 7, 1973, by 284 to 135 in the House and 75 to 18 in the Senate. It became Public Law 93-148 and sits today in Title 50 of the U.S. Code, sections 1541 to 1548.

No court has struck it down, and no court has enforced its 60-day clock against a president either. Every president since Nixon has said the law intrudes on the commander in chief’s powers, yet presidents still file the 48-hour reports, usually describing them as “consistent with” the law rather than required by it.

One part has lost its force. In 1983 the Supreme Court ruled in INS v. Chadha that Congress cannot overturn executive action with a measure the president never signs, which undercut the concurrent resolution route. Congress answered the same year by giving joint resolutions on troop withdrawals a fast track, but a joint resolution must be signed by the president or passed over a veto. Presidents have also run past the clock: the 1999 Kosovo air campaign lasted 78 days, and in 2011 the Obama administration argued that its Libya operations did not amount to “hostilities” at all.

The 60-day clock on the Iran war ran out on May 1, 2026, and the White House says it no longer applies. Trump notified Congress of the strikes on March 2. On May 1 he wrote to House Speaker Mike Johnson and Senate President pro tempore Chuck Grassley that there had been no exchange of fire between U.S. forces and Iran since the April 7 ceasefire, and that the hostilities that began on February 28 “have terminated.” Defense Secretary Pete Hegseth told senators that a ceasefire “pauses or stops” the clock. The U.S. naval blockade of Iran’s ports, first enforced on April 13, was lifted on June 18 and reimposed on July 14, and it was still in force in November.

Congress has used the law’s voting procedures again and again. The Senate rejected Senator Tim Kaine’s resolution 47 to 53 on March 4, with Republican Rand Paul voting for it and Democrat John Fetterman against, and rejected another by the same margin on March 24. On June 3 the House passed a concurrent resolution directing the president to remove U.S. forces from hostilities against Iran, 215 to 208, with four Republicans in favor: Tom Barrett, Warren Davidson, Brian Fitzpatrick and Thomas Massie. The Senate adopted it 50 to 48 on June 23, the first time the Senate has passed an Iran war powers measure in this war. A White House official said the vote had “no significance” because hostilities “terminated with the ceasefire on April 7th.”

The House passed another resolution 214 to 208 on July 23. The Senate’s last vote before the midterms failed 49 to 50 on September 24, with Republicans Susan Collins, Lisa Murkowski, Rand Paul and Thom Tillis voting in favor and Fetterman against. Because the measures that passed were concurrent resolutions, none reached Trump’s desk and none binds him.

Yes. A joint resolution goes to the president, and a veto stands unless two thirds of both the House and the Senate vote to override it. Trump has done this before on Iran. In 2020 the Senate passed Kaine’s Iran war powers resolution 55 to 45 on February 13 and the House passed it 227 to 186 on March 11. Trump vetoed it on May 6, 2020, and the Senate override failed 49 to 44 the next day, far short of two thirds. In April 2019 he had also vetoed a resolution to end U.S. support for the Saudi-led war in Yemen.

After the midterm results he made the same point to the incoming majority. “I have total veto power and I’m sure we’ll be able to work things out,” he said in a telephone call on November 4, adding: “Otherwise I’d just veto everything and they’re not gonna want that.”

It can pass a binding joint resolution, force Trump to veto it in public, and use the power of the purse, which is harder for a veto to block. The new Congress sits on January 3, 2027. A joint resolution ordering U.S. forces out of hostilities against Iran needs only simple majorities to reach the president, and the fast-track rules let its sponsors force a vote. Without two thirds in each chamber to override, the veto would decide it.

Money is the stronger lever. Congress writes the defense budget and any war supplemental, and it can bar funds for specific operations, as it did in 1973 when it cut off money for U.S. combat in Southeast Asia. A president can veto a spending bill too, but refusing to sign the bill that pays the armed forces carries a cost that a stand-alone war resolution does not. Until then, Trump says the United States has no immediate plan to strike Iran but is “locked and loaded.”