The U.S. Senate advanced a War Powers Resolution on May 19, 2026, intended to force an end to President Trump’s military hostilities with Iran, according to a press release from the office of Senator Tim Kaine. The move follows months of legislative attempts in the House of Representatives to curb executive war-making authority, including two failed concurrent resolutions.
Senate resolution details
The Senate vote, led by Democratic leaders including Senator Chuck Schumer and Senators Adam Schiff, Cory Booker, and Tammy Duckworth, sought to mandate the removal of United States Armed Forces from hostilities against the Islamic Republic of Iran. The resolution's proponents argued that the conflict has lacked a clear strategy, legal authority, or congressional authorization.
Arguments regarding war costs
Senator Tim Kaine stated that the war in Iran has imposed a "tremendous cost on the American people," specifically citing the deaths and injuries of servicemembers and rising gas prices. Senator Adam Schiff echoed these concerns during the May 19 vote, noting that after 80 days of conflict, there remains no explanation to the American people regarding why they should endure the costs in lives lost and damage to national security.
Failed House legislative attempts
Despite progress in the Senate, recent legislative efforts in the House of Representatives have stalled. According to congressional records, H.Con.Res.38, a resolution introduced by Representative Thomas Massie on June 17, 2025, failed to pass the House on March 5, 2026, with a vote of 212 to 219.
Details of H.Con.Res.38
This resolution specifically directed the President, pursuant to section 5(c) of the War Powers Resolution, to terminate the use of U.S. Armed Forces from hostilities against Iran or any part of the Iranian government or military, unless a declaration of war or authorization for the use of military force had been enacted. The text of H.Con.Res.38 noted that such a directive would not prevent the United States from defending itself against imminent attacks.
Failure of H.Con.Res.40
A second House attempt, H.Con.Res.40, also failed to gain passage. Introduced on June 23, 2025, by Representative Gregory W. Meeks and several colleagues, the resolution sought to direct the President to remove U.S. Armed Forces from hostilities with Iran. On April 16, 2026, the House rejected the measure with a vote of 213 to 214.
Provisions for national defense
Like its predecessor, H.Con.Res.40 included provisions allowing for the use of military force necessary to defend the United States or its allies and partners from imminent attack, provided the President complies with the requirements of the War Powers Resolution.
While Democrats have pushed for the resolution to end the conflict, some Republican lawmakers have focused on the constitutional necessity of congressional oversight. In a February 2020 speech regarding Iran war powers, Senator Mike Lee of Utah argued that Congress must reassert its role in the war-making process to ensure accountability.
Senator Lee stated that while the President serves as Commander-in-Chief, the power to declare war resides exclusively with Congress. He argued that even if a President is viewed as a restrained leader, Congress has a duty to prevent the executive branch from conducting offensive military strikes without explicit authorization. Lee emphasized that intelligence-sharing is vital so that Congress can determine whether to provide further authority for offensive force.
The debate in the Senate also highlighted the economic and human costs of the ongoing conflict. Senator Tammy Duckworth noted that the war has already cost $29 billion and resulted in the deaths of 14 U.S. troops. She criticized the administration's lack of a coherent strategy, describing recent presidential rhetoric regarding strikes as the actions of an incompetent leader.
Other senators, including Senator Andy Kim and Senator Chris Murphy, emphasized that the decision to engage in military operations should not rest with a single individual. Senator Murphy noted that the power to decide when to send troops overseas and expend taxpayer money is a fundamental responsibility of the legislative branch.
The legislative landscape remains divided between efforts to end active hostilities and the push for greater congressional oversight. While the Senate successfully advanced its resolution in May 2026, the failure of both H.Con.Res.38 and H.Con.Res.40 in the House illustrates the difficulty in achieving a consensus on the future of U.S. military engagement in Iran.
