The Senate on Thursday rejected a resolution that would have directed President Trump to end U.S. military involvement in Iran, despite mounting frustration among Republican lawmakers over the conflict's duration and economic toll. The 49-50 vote fell short of the simple majority needed for passage, with only four Republicans—Sens. Susan Collins (Maine), Lisa Murkowski (Alaska), Rand Paul (Ky.), and Thom Tillis (N.C.)—joining nearly all Democrats in support.
The measure, a concurrent resolution previously passed by the House in July, aimed to withdraw U.S. troops from hostilities without congressional authorization. Democratic Sen. John Fetterman (Pa.), a staunch Israel ally, was the lone Democrat to oppose it, while Sen. Angela Alsobrooks (Md.) missed the vote.
Tillis, who voted for the resolution for the first time, cited the war's prolonged nature and its political fallout. "We're reaching a point where we just need answers. We got to know what success looks like," he told The Hill. He noted a "consistently downward-trending negative reaction" from the public since strikes began in February, adding, "We don't know how long it's going to go. So, we're afraid it could be a forever war. It's a war that's obviously hurting people economically. Why are we doing this? What is the goal?"
Public support for the conflict has eroded, particularly among Republicans. A CNN/SSRS poll this month showed GOP approval down more than 10 points since March, reflecting broader concerns about rising fuel costs.
The decisive no vote came from Sen. Bill Cassidy (R-La.), who had appeared undecided earlier in the day. Cassidy, who lost his primary in May, was seen in intense discussions with Senate Majority Leader John Thune (R-S.D.) and GOP Whip John Barrasso (R-Wyo.) before emerging to vote no. He dismissed speculation of pressure, calling it "nonsense."
Cassidy's vote marked a reversal from his June support for a similar measure, which had sparked a heated confrontation with Trump during a private meeting. He later switched his position after receiving a briefing from Vice President Vance and envoy Steve Witkoff, saying they provided the information he needed.
The war's cost has become a central issue. The Congressional Budget Office estimates the Pentagon has spent $38 billion through Aug. 1. Gas prices have surged from below $3 per gallon before the conflict to $4.50 now, while diesel hit a record high of $6.52 this week.
The House passed another war powers resolution on Sept. 15 with seven Republicans joining Democrats, but the Senate's action signals ongoing GOP resistance to binding constraints on the president's war-making authority. The failed vote underscores a party split between those prioritizing executive flexibility and those facing electoral pressure over economic pain. As the conflict drags on, Republican senators are increasingly caught between loyalty to Trump and voter discontent, a tension likely to intensify as campaign season approaches.
