In a historic bipartisan rebuke of the ongoing military conflict between the United States and Iran that launched in late February, the Republican-controlled U.S. Senate has passed a concurrent resolution ordering President Donald Trump to either halt all military operations against Iran or secure formal congressional authorization to continue any offensive action. The final vote tally stood at 50 to 48 on Tuesday, with four sitting Republican senators breaking ranks with their party leadership to join Democrats in supporting the measure. The outcome marks the first public, bipartisan show of opposition to the war since hostilities began four months ago, following an earlier House of Representatives vote in June that also saw cross-party support for the same resolution.
Despite its passage in both chambers of Congress, the measure carries no legal weight and will not be forwarded to the White House for Trump’s signature, rendering it largely symbolic in its current form. Legal scholars note that the resolution could still face court challenges, however, and its passage marks an unprecedented milestone: this is the first time since the 1973 War Powers Resolution was enacted that both chambers of Congress have approved a concurrent resolution directing a sitting president to end an active military engagement.
The resolution’s approval comes amid growing national and international pressure on the Trump administration to wrap up the conflict, which has sent global energy markets into turmoil. Iran’s closure of the Strait of Hormuz — a critical global shipping chokepoint that carries roughly 20% of the world’s crude oil and liquefied natural gas supplies — has caused petrol prices to spike sharply across the United States, while public polling shows steadily rising opposition to the war among American voters.
Just one week before the Senate vote, leaders from both Washington and Tehran signed a memorandum of understanding to extend an existing ceasefire and work toward a full end to hostilities. Clashes over the fine details of the interim agreement continue, however, leaving the final status of the conflict uncertain.
The vote also lays bare deep internal divisions within the Republican Party, which currently holds a narrow majority in the Senate. Four GOP senators — Rand Paul, Lisa Murkowski, Susan Collins, and Bill Cassidy — crossed the aisle to vote with Democrats, while two additional Republican senators, including Senate Republican leader Mitch McConnell, were absent from the vote. Only one Democratic senator, John Fetterman, broke with his party to vote against the resolution. The combination of defections and absences created the narrow margin needed for the resolution to pass.
Under existing U.S. federal law, the president is required to secure congressional approval for any military engagement that lasts longer than 60 days. The U.S., alongside Israel, launched the initial strikes against Iran on February 28. The Trump administration has argued that multiple ceasefire agreements have reset the 60-day clock, and the president can also extend the deadline by an additional 30 days on national security grounds.
To recap the timeline of the conflict: After the U.S.-Israeli strikes in February, Iran launched retaliatory attacks against Israel and U.S. allied states in the Persian Gulf, before closing the Strait of Hormuz to global shipping. In April, Washington announced a full naval blockade of all commercial traffic moving to and from Iran’s coast. An initial ceasefire reached in April collapsed almost immediately, leading to last week’s interim MoU aimed at securing a permanent end to fighting. The BBC has reached out to the White House for comment on Tuesday’s Senate vote, with no immediate response as of publication.