The constitutional split
The framers divided war powers between the two political branches. Article I, Section 8 gives Congress the authority to "declare War," raise armies, and fund military operations. Article II names the president as "Commander in Chief" of the armed forces. That division has produced more than two centuries of debate about where authorization to start or continue a conflict must come from.
What the War Powers Resolution says
Passed over President Nixon's veto in 1973, the War Powers Resolution requires the president to notify Congress within 48 hours of introducing U.S. armed forces into hostilities. It also requires those forces to be withdrawn within 60 days (with a 30-day extension for safe removal) unless Congress declares war, enacts a specific authorization for the use of military force (AUMF), or extends the deadline.
The role of existing AUMFs
Congress passed AUMFs in 2001, targeting those responsible for the September 11 attacks, and in 2002, authorizing action in Iraq. Several administrations of both parties have cited these statutes as legal grounding for a range of operations across the Middle East. Critics argue the authorizations have been stretched far beyond their original purpose; supporters say they remain valid tools for ongoing counterterrorism missions.
The current Iran situation
According to Reuters reporting on congressional hearings with Secretary of State Marco Rubio, U.S. military operations connected to the Iran conflict have entered their fourth month as of June 2026. That timeline has put the War Powers Resolution's 60-day clock at the center of debate, with some lawmakers pressing for a vote on a new authorization and others contending no new vote is legally required.
The case for requiring new authorization
Supporters of a fresh vote argue that the Constitution vests the decision to commit the country to sustained hostilities in the legislature, not the executive. They contend that AUMFs written for Al Qaeda or Saddam Hussein's government cannot reasonably cover a conflict with Iran, and that an explicit vote ensures public deliberation and accountability before further escalation.
The case against requiring new authorization
Opponents argue that the president's Article II powers as commander in chief include the authority to defend U.S. personnel and interests without waiting for Congress. They say the 2001 and 2002 AUMFs, combined with the president's inherent self-defense authority, supply sufficient legal basis for current operations, and that requiring a new vote could signal division to adversaries or constrain operational flexibility.
Recent precedent
Congress has weighed in on Iran before. Senate Joint Resolutions to constrain presidential military action against Iran passed in 2019 and 2020 with bipartisan majorities, but both were vetoed and the Senate did not muster the two-thirds needed to override. Those votes illustrate that the question of who authorizes military action against Iran is a recurring one, not unique to any single administration.
What a vote would look like
A binding measure would typically take the form of either a new AUMF authorizing specified operations, or a joint resolution under the War Powers Resolution directing the president to remove forces from hostilities. Either approach would need to clear both chambers, and to take effect over a presidential veto would require two-thirds support in the House and Senate.