War Powers Resolution (1973)
Americans had grown concerned that the country was in undeclared wars in Korea and Vietnam for many years. Article I, section 8 of the Constitution gives Congress the power to declare war, while Article II section 2 gives the President the authority as commander-in-chief of the military.
The War Powers Resolution was passed as a response to executive interpretation of and action under the Gulf of Tonkin Resolution. The Resolution set out to define the balance of power between the legislative and executive branches. The President must consult Congress before the start of hostilities, and report regularly on the deployment. Further, the President must withdraw forces within 60 days if Congress has not declared war or authorized the use of force. Congress passed this law over President Nixon’s veto.