Glossary

Authorization for Use of Military Force

A law in which Congress authorizes the president to use military force, such as the 2001 and 2002 authorizations.

Also called: AUMF, authorization for use of military force, 2001 AUMF

An Authorization for Use of Military Force (AUMF) is a statute through which Congress approves military action without a formal declaration of war, which has not been issued since World War II. It is meant to satisfy Congress's constitutional role and the requirements of the War Powers Resolution.

Two are most important today. The 2001 AUMF, enacted days after the September 11 attacks, authorizes force against those who "planned, authorized, committed, or aided" the attacks and those who harbored them. Administrations of both parties have read it to cover al-Qaeda and affiliated groups in many countries, including ISIS. The 2002 AUMF authorized force against Iraq, and proposals to repeal it and the 1991 Gulf War authorization have recurred; check the current status of each.

Critics, including members of both parties, argue that the 2001 authorization has been stretched far beyond its original intent and that Congress has abdicated its war power. Defenders of broad authority say that flexibility is needed against shifting threats. Proposals to replace or sunset it have not passed. Congress's role in war is a central separation of powers question.

Last reviewed November 8, 2026

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Related terms

War Powers Resolution A 1973 law limiting the president's ability to commit U.S. forces to hostilities without congressional approval. Separation of powers The constitutional division of government into legislative, executive and judicial branches, each with its own distinct powers. Checks and balances The constitutional design giving each branch of government ways to limit the others, so that no branch dominates. Impeachment The constitutional process by which the House charges a federal official with misconduct and the Senate tries the charges.