A resolution by the US Congress, giving the President authority to take all necessary measures to repel any attack against the forces of the USA. The resolution was made in response to an alleged attack by North Vietnam patrol boats against the US destroyer Maddox in the Gulf of Tonkin. The US involvement in the fighting in the Vietnam War followed. Subsequent investigation revealed that the intelligence information on which it was based was inaccurate and, following the war, the War Powers Act was passed in 1973. This restricts the time a President can commit US troops without Congressional approval to 60 days.