The United States Senate rejected House Concurrent Resolution 89 by 49 votes to 50 on Thursday 24 September 2026, one vote short of ordering American forces out of hostilities with Iran1. The measure runs on the War Powers Resolution, the 1973 law that lets Congress order forces out of a conflict it never authorised.
Four Republicans crossed: Rand Paul, Susan Collins, Lisa Murkowski and Thom Tillis2. Three of them had backed the previous Senate attempt, on 30 July, which also failed by one vote, 49 to 503. Tillis had never crossed before. He voted for an Iran War Powers Resolution for the first time, pointing to the war's economic cost and to opposition from voters45. "We got to know what success looks like," he said. "There's never been any way to measure what success looks like"6. Tillis will not stand for a third term.
That is why a repeated margin is not a repeated result. The arithmetic has not moved across three attempts, but the roster underneath it has, and a senator who has never voted this way before is a harder signal than a tally. Tillis's stated reason is cost and constituency rather than constitutional principle, which is the reason most likely to reach colleagues who are seeking re-election.
The instrument itself binds nothing. A concurrent resolution is never presented to the President, so the count measures Senate opinion and leaves the use of force untouched. The other legislature in this war is in the same position: the Majlis holds a bill to quit the nuclear treaty, filed under its fastest procedure and still unscheduled on the Speaker's desk. Each chamber holds an instrument it has not managed to fire. The Senate's own roll-call server returned a stub rather than the sheet, so the tally and the four names rest on press reporting7.
