The Senate narrowly rejected a resolution on Thursday aimed at directing President Donald Trump to end the war with Iran unless he obtains explicit congressional authorization. The measure, which had previously passed the House of Representatives in July, was defeated by a 50-49 vote, highlighting ongoing divisions within both parties over the conflict.
Four Republicans—Senators Susan Collins of Maine, Rand Paul of Kentucky, Lisa Murkowski of Alaska, and Thom Tillis of North Carolina—joined Democrats in supporting the resolution. Senator John Fetterman of Pennsylvania was the lone Democrat to oppose it. Tillis’s vote represented the latest break from GOP ranks on the issue, reflecting a small but growing faction challenging the president’s authority to continue military action without a formal approval from Congress.
Conversely, Senator Bill Cassidy of Louisiana reversed his earlier stance and voted against the measure, aligning with the Republican majority and contributing to its narrow defeat. This marked the twentieth time Congress has taken a vote on similar resolutions since the onset of hostilities on February 28.
The vote comes amid increasing voter concern over the ongoing conflict, with midterm elections just weeks away. While the Senate’s rejection blocks one avenue for rebuking the president’s approach, a separate war powers resolution remains active. The House recently approved a related measure requiring the president to withdraw U.S. forces from hostilities against Iran, which garnered bipartisan support including seven Republicans. That measure could still be considered by the Senate, offering another chance for Congress to express opposition to the war.
Although such resolutions do not have the force of law, they serve as political statements against the administration’s handling of the conflict. Over time, more Republicans in both chambers have voiced criticism of the war, seeking to address constituent concerns about its impact and to distance themselves from the president ahead of November’s elections.
Democrats have repeatedly introduced measures to curtail Mr. Trump’s war powers, aiming to compel him to seek congressional authorization before continuing military operations. However, the White House has maintained that the president possesses adequate constitutional authority to conduct such actions. Despite several congressional votes opposing the war, the administration has pressed forward with military activities, leaving these resolutions largely symbolic.
When the Senate and House last passed a resolution directing an end to hostilities in June, Mr. Trump publicly criticized Republicans who supported it, urging them to reverse their positions. Nonetheless, the partisan willingness to challenge the president on this issue has slowly increased, resulting in more frequent bipartisan opposition even though practical effects on policy remain limited.
The continued pattern of votes illustrates the challenges Congress faces in asserting its constitutional role over war powers amid executive resistance, underscoring the complex interplay between legislative oversight and presidential military authority.