War Powers and the Iran War: What Congress Can and Can't Do

The war with Iran began on February 28, 2026, with U.S. and Israeli strikes on Iranian targets [1]. Congress never voted to authorize it. Since then the House has voted more than once to end U.S. involvement, and the Senate has repeatedly fallen just short. This guide explains the law behind those votes, why they have not stopped the war, and what lawmakers could still do. It reflects the votes we could confirm through late September 2026.

What the Constitution Says

The Constitution splits war powers between the branches. Article I gives Congress the power “to declare War,” to raise and fund armies, and to make rules for the armed forces. Article II makes the president “Commander in Chief” [4]. For most of American history, that division was settled by politics more than by courts. Congress last formally declared war at the start of World War II, and since then presidents have sent forces into combat many times on their own authority as commander in chief, sometimes with a congressional authorization and sometimes without one [2].

The 1973 War Powers Resolution

As the Vietnam War dragged on, Congress tried to reclaim its role. In 1973 it passed the War Powers Resolution over President Richard Nixon’s veto. The law has three main parts [2]:

Notice: When the president sends U.S. forces into hostilities without a declaration of war, he must report to Congress within 48 hours.
A 60-day clock: Unless Congress declares war or authorizes the operation, the president must end the use of those forces within 60 days. He can take 30 more days if needed to withdraw them safely.
A way to order withdrawal: Congress can direct the president to remove forces. Under current practice that takes a joint resolution, which, like any bill, the president can veto.

That last point is the catch. Overriding a veto requires two-thirds of both chambers, and no war powers resolution has ever overcome one [2]. In Trump’s first term, Congress passed two: one in 2019 to end U.S. support for Saudi Arabia’s war in Yemen, and one in 2020 after the killing of the Iranian general Qasem Soleimani. Trump vetoed both [2].

The 2026 Votes

The 60-day deadline for the operation, which the Pentagon named Operation Epic Fury, arrived on May 1. The administration argued that hostilities had “terminated” because of a ceasefire with Iran, even though U.S. forces stayed deployed in the region and clashes continued periodically [2].

June 3, 2026: The House passed a war powers resolution 215–208. Four Republicans, Brian Fitzpatrick of Pennsylvania, Tom Barrett of Michigan, Warren Davidson of Ohio and Thomas Massie of Kentucky, joined Democrats. “We’re past the 60 days, so you have two choices,” Fitzpatrick said. “You either follow the law or you change the law” [1]. Trump called it “a meaningless vote.”
July and September: The House passed another resolution in July, 214–208, and in September a separate resolution drew 220 votes, with a record seven Republicans in support [3].
September 24, 2026: The Senate defeated the House-passed measure, 49–50. Republicans Susan Collins, Lisa Murkowski, Rand Paul and Thom Tillis voted for it, and Democrat John Fetterman voted against [3].

Why the Votes Haven’t Ended the War

Even if both chambers passed the same resolution, it would need the president’s signature or a veto override to take effect, and the votes so far are nowhere near two-thirds [2]. The resolutions are therefore mostly symbolic, though they carry political weight: they put lawmakers on record, and they show cracks in Republican support. NPR reported that at least 19 U.S. service members had been killed by late September, according to the Defense Department, and that Republican candidates in close Senate races, including Rep. Ashley Hinson in Iowa and Mike Rogers in Michigan, had begun calling for the war to end as fuel prices rose [3].

What Congress Could Still Do

Cut off funding. Congress controls spending, and it could deny money for the operation. A funding cutoff would also face a likely veto [2].
Authorize the war. Supporters of the operation could pass an authorization for the use of military force, which would end the legal dispute on Congress’s terms. The administration has not asked for one [2].
Go to court. Some experts expect any serious confrontation to reach the courts, though judges have long avoided ruling on the War Powers Resolution itself [2].
Wait for the election. Control of Congress is on the ballot on November 3, 2026. A Congress with different majorities could hold oversight hearings and use the budget, though overriding a veto would still require two-thirds of both chambers. For more on what is at stake, see our guide to the 2026 midterm elections.

The Bigger Picture

The fight over Iran is the latest round of a debate as old as the Constitution. Presidents of both parties have argued that the commander in chief can act without asking first, and Congresses of both parties have usually let them. What makes 2026 unusual is the scale and length of the conflict, and the growing number of members of the president’s own party willing to vote against it. To understand how these powers are divided, see our explainer on how the U.S. government works.