Following disputed reports of North Vietnamese attacks on U.S. destroyers, Congress passed the Gulf of Tonkin Resolution almost unanimously, authorizing the president to take 'all necessary measures' to repel aggression in Southeast Asia without a formal declaration of war. It became the legal basis for the massive escalation of American combat operations in Vietnam over the following decade.
The resolution followed murky naval incidents in early August: a real skirmish on August 2 between the USS Maddox and North Vietnamese torpedo boats, and a second alleged attack on August 4 that later evidence, including sonar operators' own doubts at the time, suggested may never have happened. Johnson nonetheless ordered retaliatory airstrikes and asked Congress for sweeping authority.
The resolution passed the Senate 88 to 2 and the House unanimously, with only Senators Wayne Morse and Ernest Gruening dissenting, both warning prophetically that it amounted to a blank check for war. Robert McNamara later admitted the intelligence behind the second incident was flawed.
Over the next decade, successive administrations cited the resolution to justify deploying over 500,000 troops without ever seeking a formal declaration of war from Congress. Congress finally repealed it in 1971, amid growing disillusionment, and the episode became a landmark case study in how contested intelligence can trigger open-ended military commitments.
Key people: Lyndon B. Johnson