Gulf of Tonkin incident

On 2 August 1964, a U.S. Navy destroyer collecting signals intelligence off North Vietnam clashed with three North Vietnamese naval vessels in the Gulf of Tonkin. On the night of 4 August, two U.S. destroyers reported being attacked, but later investigation revealed that no such attack occurred. Congress responded to the reported attacks by passing the Gulf of Tonkin Resolution, which authorized a major escalation of U.S. military involvement in the Vietnam War.