For the first time since the War Powers Resolution was enacted in 1973, both chambers of the US Congress have approved a measure directing a president to end a military action. The symbolic vote against Donald Trump's war with Iran has exposed the limits of legislative power over the commander-in-chief, and raised questions about how – or whether – Congress can stop a president determined to keep fighting.
The War Powers Resolution of 1973 is a federal law intended to check the president's authority to commit the United States to armed conflict without congressional approval. It requires the president to notify Congress within 48 hours of deploying forces and limits hostilities to 60 days (with a 30-day withdrawal period) unless Congress authorises the action or declares war. The recent concurrent resolution – passed by the Senate 50-48 and the House 215-208 – expresses the sense of Congress that the president should cease hostilities in Iran or seek authorisation. But a concurrent resolution does not go to the president for signature and has no force of law. In 2019, Trump vetoed a binding joint resolution on Yemen; this time, the measure is purely symbolic, what Middle East analyst Laura Blumenfeld called "more of a slap on a wrist than a handcuff".
“Explains the US War Powers Resolution, its history, and the limits of congressional power to stop a president's military action.”
The resolution reflects growing unease among Republicans and Democrats over the Iran conflict, which began on February 28 and is now entering its fifth month. A poll released on the day of the Senate vote showed just one in four Americans believe the war was worth its costs. Four Republican senators – Rand Paul, Lisa Murkowski, Susan Collins and Bill Cassidy – joined Democrats in support. Democratic senator John Fetterman was the only member of his party to vote against it. The White House dismissed the vote, noting that a ceasefire was agreed on April 7 and that two Republican senators were absent. But Democrats point to the US Constitution, which gives Congress the power to declare war. "Congress has to own this responsibility," said Senator Tim Kaine.
For UK readers, the dispute matters because the US is the UK's most important security ally. The special relationship – already strained by trade tariffs and differing approaches to diplomacy – could be tested further if a future UK prime minister, such as Andy Burnham, has to decide how to deal with a President Trump who has shown he is willing to ignore congressional sentiment. The UK also has interests in Gulf stability; the UN has said it will evacuate sailors stranded in the Strait of Hormuz. Legal experts, including Scott Anderson of the Brookings Institution, say the constitutionality of the War Powers Act will likely be settled in the courts, but it is unclear who would have standing to sue. "The executive branch will likely ignore it on constitutional grounds," Anderson said.
Q: What is the War Powers Resolution? It is a 1973 US federal law designed to limit the president's ability to send troops into hostilities without congressional approval. It requires notification within 48 hours and limits deployments to 60 days (plus 30 for withdrawal) unless Congress authorises the action.
Q: Does the recent congressional vote stop the war in Iran? No. The resolution is a concurrent resolution, which expresses the will of Congress but does not go to the president and is not legally binding. It cannot force an end to hostilities, but it adds political pressure.
Q: Has Congress ever used this power to stop a war before? This is the first time both chambers have passed a concurrent resolution instructing a president to end military action since the War Powers Resolution was enacted. Previous attempts, such as a 2019 joint resolution on Yemen, were vetoed by President Trump.
What happens next is uncertain. Representative Gregory Meeks, who sponsored the House resolution, said he views it as binding and would pursue legal avenues. Democratic lawmakers have promised additional war powers votes to force Republicans to go on the record. Meanwhile, the Trump administration is negotiating a peace agreement with Iran and has warned it may resume hostilities if talks falter. The ultimate check may be the midterm elections, which are only months away.