Senate Republicans Block Effort to End Trump’s Iran War as GOP Support Begins to Fracture
WASHINGTON — The Senate on Thursday rejected a House-approved resolution that would have required President Donald Trump to withdraw U.S. forces from hostilities with Iran, defeating the measure even as a small but growing group of Republicans has raised concerns about the length and economic consequences of the conflict.
The resolution failed 49-50. Four Republicans — Sens. Susan Collins of Maine, Lisa Murkowski of Alaska, Rand Paul of Kentucky and Thom Tillis of North Carolina — joined most Democrats in supporting it. Sen. John Fetterman, D-Pa., was the lone Democrat to vote against the measure. Sen. Angela Alsobrooks, D-Md., did not vote.
The House previously approved the resolution 214-208 in July. The measure would have directed the president to remove U.S. forces from hostilities against Iran unless Congress specifically authorized continued military action.
Tillis' vote marked his first time backing a congressional effort to invoke war powers against the administration. He said Thursday that the conflict has continued without a clear congressional authorization or publicly defined end state.
“We’re reaching a point to where we just need answers. We got to know what success looks like,” Tillis told The Hill.
He also pointed to the political and economic consequences of the war, including higher prices for gasoline, diesel and fertilizer.
“We don’t know how long it’s going to go,” Tillis said. “So, we’re afraid it could be a forever war.”
Republican support for the conflict has shown signs of weakening as the war enters its seventh month. Recent polling has found declining support among GOP voters, while several Republican lawmakers and candidates have increasingly questioned the administration's approach.
The decisive vote came from Sen. Bill Cassidy, R-La., who had appeared uncertain about his position earlier Thursday. Cassidy ultimately voted against the resolution, helping ensure its defeat.
Cassidy spent time with Senate Majority Leader John Thune, R-S.D., in the Mansfield Room near the Senate floor before emerging to cast his vote. He also spoke with Republican Whip John Barrasso, R-Wyo.
Cassidy rejected suggestions that Republican leaders pressured him to oppose the measure, calling such speculation “nonsense.”
His vote was notable because Cassidy had previously supported a similar war powers resolution in June alongside Collins, Murkowski and Paul. His position shifted after a subsequent meeting with Trump and a classified briefing from Vice President JD Vance and special envoy Steve Witkoff.
The June vote triggered a contentious confrontation between Trump and Cassidy at the Capitol. Cassidy later supported another Iran war powers measure after receiving additional administration briefings.
Paul, meanwhile, also altered his position during an earlier vote after Trump publicly expressed strong opposition to congressional efforts to limit his authority over the conflict.
The financial cost of the war has also emerged as a significant concern. The Congressional Budget Office said last week that the Defense Department had incurred approximately $38 billion in costs through Aug. 1. The estimate includes expenditures for replacing munitions and equipment, increased flying hours, fuel and other military operations.
CBO said the conflict could continue adding roughly $2 billion to $3 billion in costs each month, depending on the intensity of fighting.
Fuel prices have become another major political issue surrounding the conflict, with Republicans in competitive races increasingly highlighting the effect of the war on household and business costs.
The House approved another Iran war powers resolution Sept. 15 by a 220-204 vote, with seven Republicans joining Democrats. The Senate's action Thursday leaves the latest House-passed measure blocked despite the emergence of additional Republican opposition to the administration's handling of the conflict.