The Senate on Thursday rejected a resolution that would have directed President Donald Trump to end U.S. hostilities with Iran absent new congressional authorization. The measure failed on a 49-50 vote, with most Republicans opposing it and four senators from the party breaking ranks to support the effort.

Senate Democrats led the concurrent resolution, which passed the House in July by a 214-208 margin. It sought to invoke the War Powers Resolution of 1973 to require the withdrawal of U.S. forces from hostilities against Iran unless Congress explicitly approved continued action. As a concurrent resolution, it would not have required the president's signature and carried no legal force to bind the executive branch.

The vote split showed near-unanimous Democratic support, with 48 Democrats voting yes and Sen. John Fetterman of Pennsylvania as the sole Democrat opposing it. Four Republicans joined the yes column: Sens. Rand Paul of Kentucky, Susan Collins of Maine, Lisa Murkowski of Alaska, and Thom Tillis of North Carolina. The remaining 46 Republicans voted no, with one senator not voting.

Republican leaders and most members of the party stood with the administration's position that the resolution lacks constitutional authority to restrict presidential powers as commander in chief. The Trump administration has maintained that similar prior measures do not constrain military operations and has continued strikes in response to Iranian actions, including disruptions in the Strait of Hormuz that have contributed to higher energy and food prices in the United States.

The Senate has considered comparable Iran war powers resolutions multiple times since the conflict began, approving them on only a few occasions. Democrats have used the votes to highlight Republican divisions and the war's costs, which includes the deaths of at least 19 U.S. service members so far. Some Republicans in competitive races have expressed concerns about the conflict's duration and domestic impacts.

The outcome preserves the administration's flexibility in managing the Iran situation without additional legislative constraints from Congress at this stage.