U.S. Senate rejects resolution to end Iran war without congressional approval

U.S. Senate rejects resolution to end Iran war without congressional approval
Iranian Americans and NCRI supporters march near the U.S. Capitol in Washington, D.C., U.S., 16 May 2026.
Reuters

The U.S. Senate narrowly rejected a resolution on Thursday that would have required President Donald Trump to end the war in Iran or seek congressional authorisation, as Democrats sought to put Republicans on the record over the increasingly unpopular conflict ahead of November's midterm elections.

The resolution was defeated 50-49, largely along party lines. Four Republicans, Susan Collins of Maine, Rand Paul of Kentucky, Thom Tillis of North Carolina and Lisa Murkowski of Alaska, voted in favour.

One Democrat, John Fetterman of Pennsylvania, voted against the resolution, which had passed the House of Representatives in July.

Vote largely symbolic

The vote was largely symbolic, as the Trump administration has not changed its policy in response to previous war powers votes.

It came two days after Trump threatened in a speech at the United Nations General Assembly that he could “annihilate the Islamic Republic”.

The U.S. Constitution gives Congress, rather than the president, the power to declare war. Democrats have argued that Trump could be drawing the United States into a prolonged conflict without setting out a clear strategy.

Republicans have said Trump's actions fall within his powers as commander-in-chief.

The conflict has also become a political issue ahead of the 3 November elections, with the war contributing to higher food and fuel prices.

A Reuters/Ipsos poll this week found that 34 per cent of respondents approved of the U.S. strikes on Iran.

Some Republicans break ranks

A small number of Republicans have broken with Trump over the war.

In the House of Representatives, the lower house of the U.S. Congress, seven Republicans joined Democrats last week in voting for a war powers resolution. Three of them, Zach Nunn and Mariannette Miller-Meeks of Iowa and Nancy Mace of South Carolina, had voted against their party's leaders on the issue for the first time.

Nunn and Miller-Meeks are facing competitive re-election races in November, when all 435 House seats and 35 of the 100 Senate seats are up for grabs. Mace is not seeking re-election after an unsuccessful campaign for governor of South Carolina.

Two Republican Senate candidates, Mike Rogers in Michigan and Ashley Hinson in Iowa, also called on Monday for a swift end to the war. Both had previously backed Trump's authority to strike Tehran.

War powers votes

The Senate has considered Iran war powers resolutions 14 times since U.S. and Israeli forces began bombing Iran on 28 February, voting in favour only twice. The House has held six votes, with three supporting an end to the conflict.

Only one resolution has passed both chambers, and the White House did not act on it.

House Democratic leader Hakeem Jeffries said Republicans in competitive races were increasingly distancing themselves from the war.

“It's interesting to me that several of them who are in tight races and on the verge of losing, including in places like Iowa or Michigan or Wisconsin, are all now starting to say the war needs to end,” Jeffries told reporters on Wednesday.

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