The US Congress meets this week to consider a Senate war powers resolution and two competing measures in the House of Representatives aimed at limiting President Donald Trump’s authority to expand US military operations against Iran without explicit congressional approval.

The Senate resolution, led by Senator Tim Kaine (Democrat–Virginia), invokes the War Powers Resolution of 1973, which was enacted during the Vietnam War to check presidential war-making authority. If adopted, it would require the termination of the US armed forces’ involvement in hostilities against Iran unless Congress authorises their continuation.

“The Constitution says we’re not supposed to be at war without a vote of Congress,” Kaine said. “The lives of our troops are at risk. We ought to come back to Washington right away and vote on this.”

In the House, Rep. Ro Khanna (Democrat–California) and Rep. Thomas Massie (Republican–Kentucky) have introduced a bipartisan resolution directing the president to remove US forces from hostilities against Iran without congressional approval.

At the same time, a separate and more cautious House approach has been backed by Rep. Josh Gottheimer (Democrat–New Jersey) and other centrists, who have stopped short of demanding an immediate halt but called for compliance with existing law and congressional consultation. Gottheimer said he expects the president to “comply with the War Powers Act.”

The votes follow coordinated US and Israeli strikes on Iranian military and political targets, an escalation that has reportedly resulted in American casualties and raised fears of a broader regional conflict.

Democratic leaders have framed their position around congressional oversight rather than immediate disengagement. Senate Minority Leader Chuck Schumer (Democrat–New York) said he had urged Secretary of State Marco Rubio to “be straight with Congress and the American people about the objectives of these strikes and what comes next,” adding that the Senate “should return to session to pass a war powers resolution.”

House Minority Leader Hakeem Jeffries (Democrat–New York) also called for classified briefings and a formal vote, saying the administration must “provide an ironclad justification for this act of war, clearly define the national security objective and articulate a plan to avoid another costly, prolonged military quagmire in the Middle East.”

Progressive lawmakers have been more direct in opposing the operation. Sen. Bernie Sanders (Independent–Vermont) and Sen. Jeff Merkley (Democrat–Oregon) have publicly declared “no war with Iran.”

But divisions are visible within the Democratic Party. Sen. John Fetterman (Democrat–Pennsylvania) said he would oppose the resolution. “It’s not necessary. Honestly, though, the entire thing, is really an empty gesture,” he said.

Among Republicans, support for the president remains strong. Sen. Tom Cotton (Republican–Arkansas), chairman of the Senate Intelligence Committee, said he expected “overwhelming support from elected Republicans in the Congress”.

However, Rep. Massie (Republican–Kentucky), who co-sponsored the House resolution, argued that the conflict is not consistent with the “America First” doctrine associated with Trump’s foreign policy.

Democrats have also questioned the clarity of the administration’s objectives. Sen. Mark Warner (Democrat–Virginia), the top Democrat on the Senate Intelligence Committee, said after meeting Rubio that the stated goals had shifted.

“We have seen the goals for this operation change now, I believe, four or five times,” Warner said. “I’m not sure which of those goals, if met, means that we’re at an endgame.”

Even if either chamber passes a resolution, Congress would likely need to override a presidential veto — requiring a two-thirds majority in both the House and Senate — a threshold that appears difficult given Republican control of both chambers.

The effort recalls Congress’s attempt in 2020 to curb presidential war powers after the US strike that killed Iranian General Qasem Soleimani, when lawmakers passed S.J.Res. 68, though it did not ultimately restrain executive action.

With partisan divisions deep and the conflict evolving, the coming votes will test Congress’s willingness — and ability — to assert its constitutional role in matters of war and peace.