The war powers resolution on the Iran war: What’s next?

For the first time during the current war with Iran, the House passed a resolution June 3 that could eventually force President Donald Trump to step back from military attacks. The House vote came about two weeks after the Senate voted to advance its own resolution, which has similar but not identical terms.

The legislative jockeying over the War Powers Resolution comes amid public opposition to the war and its effects, including higher gasoline prices from Iran’s closure of the Strait of Hormuz after the U.S. and Israeli attacks.

The House vote passed 215-208, with four Republicans — Reps. Thomas Massie of Kentucky, Tom Barrett of Michigan, Warren Davidson of Ohio and Brian Fitzpatrick of Pennsylvania — joining Democrats in supporting it.

The Senate vote, on May 19, was 50-47, with several senators not voting. Four Republicans — Susan Collins of Maine, Lisa Murkowski of Alaska, Rand Paul of Kentucky and Bill Cassidy of Louisiana joined all Democrats except Sen. John Fetterman of Pennsylvania, who sided with the bulk of Republicans. The Senate vote was a procedural one rather than a final vote; it discharged the measure from a committee, where it had been stalled.

"The Democrats are fueled by Trump Derangement Syndrome," Trump posted a day after the House vote. "They would rather have our Country fail than give me another, of many, victories. The four Republicans, that’s a whole other story - They’re GRANDSTANDERS! They should be ashamed of themselves."

For the war’s critics, the House and Senate votes amounted to progress. But there’s still a long way to go before congressional action can stop Trump from continuing the war. 

Here is a rundown of the next steps.

What is the War Powers Resolution?

Article I, Section 8 of the U.S. Constitution assigns Congress the right to declare war. The last time Congress declared war was at the beginning of World War II, when Franklin Roosevelt was president.

Since then, presidents have generally initiated military action using their constitutionally granted powers as commander in chief without an official declaration of war.

In August 1964, President Lyndon B. Johnson asked Congress to back his effort to widen the U.S. role in Vietnam. He received it with enactment of the Tonkin Gulf Resolution, which passed both chambers of Congress, including the Senate, with only two dissenting votes.

As the Vietnam War turned sour, lawmakers became increasingly frustrated at their secondary role in sending U.S. troops abroad. So in 1973, Congress passed the War Powers Resolution, which was enacted over President Richard Nixon’s veto. 

The resolution required that, in the absence of a declaration of war, the president must report to Congress within 48 hours of introducing armed forces into hostilities and must terminate the use of U.S. armed forces within 60 days unless Congress permits otherwise. If approval is not granted and the president deems it an emergency, then an additional 30 days are granted for ending operations.

In recent decades, congressional consent has usually been accomplished by the passage of an "authorization for the use of military force." Unlike his predecessors, Trump did not present Congress with an authorization request.

During Trump’s first term, Congress passed two resolutions to limit his war powers, although neither had enough votes to overcome his veto. One, in 2019, was to end U.S. support for Saudi Arabia’s war in Yemen. The other, in 2020, was to block further U.S. action after Trump ordered a strike that killed a top Iranian official, Qasem Soleimani. 

During Trump’s second term, the House and Senate have both been under Republican control, and most Republicans have been willing to let Trump pursue overseas military action without explicit congressional permission.

In June 2025, the Senate voted against advancing a war powers resolution on Iran. 

A subsequent resolution, on Trump’s decision to use military force to arrest Venezuelan leader Nicolás Maduro, narrowly failed.

What are the next steps?

The 60-day deadline to end hostilities without congressional permission arrived May 1, but, using a novel argument, Trump declared military action "terminated" because of a ceasefire between the U.S. and Iran. The move glossed over the fact that hostilities have continued periodically, with a large deployment of U.S. forces in the region and U.S. naval ships patrolling the strait.

The Senate would need 60 votes to proceed to a final vote on a war powers resolution if every senator casts a vote; that would require 10 votes beyond those who supported the May 19 vote, which is a significant hurdle.

"Party loyalty is a powerful force on Capitol Hill, and Republican leaders in the House and Senate will be strongly incentivized to let the Trump White House use military force without congressional approval," Matthew Green, a Catholic University political scientist, told PolitiFact last year.

If the Senate were to secure those 60 votes and pass the war powers resolution, the chambers would have to work out differences in the text of the bill between the two chambers, which might require additional votes. 

If both chambers pass identical versions of a war powers resolution, the measure would still require the president’s signature to take effect — something that seems unlikely based on Trump’s commitment to the war so far. 

If Trump vetoes it, the House and Senate could override the veto only with two-thirds votes in each chamber, which is well above the support demonstrated so far. No war powers resolution has ever overcome a veto.

"If enacted, the joint resolution would require the removal of forces within 30 days of enactment, excluding steps of self-defense, unless specific congressional authorization for continued action is obtained," said Steven Smith, an Arizona State University political scientist. 

Congress could go further and pass legislation denying funds for the war, but that would almost certainly be vetoed, too, requiring two-thirds from both chambers to override the veto.

What are other possible endgames?

Mark F. Cancian, a senior adviser at the Center for Strategic and International Studies, a national security think tank, said the whole issue could end up in the courts. Since the War Powers Resolution’s passage, the courts have repeatedly declined to rule on its constitutionality. 

"If Congress were to pass the legislation, the Trump administration would develop a legal rationale for not complying, and the issue would end up in front of the Supreme Court," Cancian said. "That has been their general pattern."

Still, supporters of the war powers resolutions can take some solace in some victories even if they fail to pass a measure through Congress.

"So far, these congressional efforts have been thwarted, but they have had some political effect by keeping the issue in the news and emphasizing congressional and popular opposition to the war," Cancian said.