The escalation of American involvement in Vietnam, the episodes of 2 and 4 August 1964 have proved among the most controversial and contentious. Claiming unprovoked attacks by the North Vietnamese on American ships in international waters, the Johnson administration used the episodes to seek a congressional decree authorizing retaliation against North Vietnam. Passed nearly unanimously by Congress on 7 August and signed into law three days later, the Tonkin Gulf Resolution—or Southeast Asia Resolution, as it was officially known.