The Senate rejected a measure directing President Donald Trump to remove U.S. forces from hostilities with Iran, falling one vote short Thursday in the latest test of Congress’s willingness to challenge the White House over an expanding conflict.

The official tally was 49 in favor and 50 against, with one senator absent. The result blocked congressional adoption of House Concurrent Resolution 89 after the House approved it 214-208 in July. The margin showed that congressional opposition to unilateral military action has moved close to a majority in the Republican-controlled Senate.

A vote decided across party lines

Republican Sens. Susan Collins of Maine, Lisa Murkowski of Alaska, Rand Paul of Kentucky and Thom Tillis of North Carolina voted for the measure alongside 43 Democrats and two independents. Democratic Sen. John Fetterman of Pennsylvania opposed it with 49 Republicans. Democratic Sen. Angela Alsobrooks of Maryland did not vote.

That alignment made the outcome less a conventional party-line vote than a narrow coalition contest over presidential power. The four Republicans supplied the votes that brought the resolution within reach, while Fetterman’s opposition and Alsobrooks’s absence left supporters just short. The result also extended a pattern of repeated, closely divided Iran war-powers votes documented by The Associated Press earlier this year.

The House had already done what the Senate declined to do. The federal legislative calendar records that representatives passed H.Con.Res.89 on July 23 and sent it to the Senate. Thursday’s vote therefore ended the measure’s immediate path through Congress rather than merely postponing another procedural step.

What the resolution sought to change

H.Con.Res.89 invoked Section 5(c) of the War Powers Resolution and directed the president to remove U.S. armed forces from hostilities with Iran. The underlying 1973 law declares Congress’s intent to ensure that the collective judgment of Congress and the president governs the introduction of U.S. forces into hostilities.

The vote did not authorize new military operations, approve additional spending or ratify the administration’s legal arguments. It decided whether Congress would issue a direct withdrawal command under the statutory mechanism selected by the House. Because the Senate rejected the concurrent resolution, existing operations and the executive branch’s claimed authority were left undisturbed.

The legal argument will not disappear with this vote. Presidents of both parties have disputed congressional efforts to compel military withdrawals, and concurrent resolutions face an additional constitutional question because they do not go to the president for a signature. Supporters nevertheless use these measures to force recorded votes and establish whether lawmakers consent to ongoing hostilities.

The political stakes are widening

The vote came as the administration faces pressure over the duration, cost and purpose of the Iran conflict. PBS NewsHour’s coverage framed Thursday’s debate against higher gasoline prices and the approaching midterm elections, tying an institutional dispute over war powers to concerns voters encounter directly.

For Republicans, the roll call exposed a limited but persistent break with the White House. Collins, Murkowski and Paul have repeatedly questioned prolonged hostilities without clearer congressional authorization. Tillis’s vote expanded that group on Thursday. But the Republican majority still held, and the chamber did not deliver the rebuke that the House approved two months earlier.

For Democrats, the result showed both the potential and the limits of a strategy built around repeated votes. Nearly the entire caucus supported the resolution, and four Republicans crossed party lines. Yet a single Democratic defection, combined with one absence, was enough to defeat it. That leaves Democrats able to argue that opposition is growing, but unable to claim Congress has withdrawn its political support.

Diplomacy complicates the congressional debate

The vote also arrived while a possible diplomatic channel remained open. A senior Iranian official told Reuters on Tuesday that Tehran could reopen the Strait of Hormuz within seven days if Washington reduced military pressure and lifted its blockade on Iranian ports. The official said Iran’s delegation at the United Nations had authority to pursue talks through mediators.

That proposal has not produced an agreement, and its conditions are politically difficult for the White House. It nevertheless adds another dimension to the war-powers argument. Supporters of withdrawal can point to diplomacy as an alternative to continued hostilities; administration allies can argue that military pressure is what created leverage for negotiations. Thursday’s vote resolved neither interpretation.

What happens next

The rejected resolution imposes no new limit on the president. Congress could try again through another war-powers measure, restrictions in a defense or spending bill, or oversight hearings focused on legal authority, objectives and costs. Each path would require a coalition at least one vote stronger in the Senate and, for ordinary legislation, enough support to overcome a presidential veto.

The more immediate consequence is political. Every senator is now on record in a 49-50 vote over whether U.S. forces should remain in hostilities with Iran. If the conflict expands, casualties rise, fuel prices remain elevated or diplomacy stalls, Thursday’s margin ensures that the next congressional challenge will begin within striking distance of passage.