When the U.S. Senate passes a War Powers resolution limiting presidential authority to wage war against Iran

My median prediction for the next Senate passage of an Iran War Powers resolution is 15th January 2027 because Polymarket pricing favours Democrats taking Senate control in the incoming Congress.

In late July 2026, the U.S. House of Representatives passed a War Powers resolution (by a vote of 214-208) aimed at constraining President Donald Trump's ability to wage war against Iran without explicit congressional approval. The vote followed the breakdown of a temporary U.S.-Iran ceasefire in early July and months of ongoing conflict. Senate Minority Leader Chuck Schumer has indicated that Democrats intend to force a similar War Powers vote in the Senate. A Senate passage of the resolution could signal significant domestic political resistance to the ongoing war, carrying implications for U.S. fiscal policy and defense spending.

This question resolves on the calendar date that the U.S. Senate passes a War Powers resolution (either as a joint or concurrent resolution) that explicitly seeks to limit the President's authority to engage in hostilities against Iran, requires congressional authorization for further military action against Iran, or directs the removal of U.S. Armed Forces from hostilities involving Iran. The date of the successful Senate floor vote determines the resolution date.