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Gulf of Tonkin Resolution (1964)

Article I, section 8 of the Constitution gives the power “to declare war” to Congress. This joint resolution of Congress, which passed almost unanimously in both houses, said, “The Congress approves and supports the determination of the President, as commander in chief, to take all necessary measures to repel any armed attack against the forces of the United States and to prevent further aggression.” This resolution led to increased American involvement in the Vietnam War and, in the view of many, greatly expanded executive power to wage war.

The Vietnamese attack on American ships that provoked the resolution, known as the Gulf of Tonkin incident, was later held by the National Security Agency to have been greatly exaggerated, or perhaps not to have occurred at all.