The single notable element of actual increased U.S. involvement in the Vietnam War during 1964 was a program of covert GVN operations, designed to impose "progressively escalating pressure" upon the North, and initiated on a small and essentially ineffective scale in February. The active U.S. role in the few covert operations that were carried out was limited essentially to planning, equipping, and training of the GVN forces involved, but U.S. responsibility for the launching and conduct of these activities was unequivocal and carried with it an implicit symbolic and psychological intensification of the U.S. commitment.
On July 31, 1964, and after a six month suspension, the American destroyer USS Maddox (DD-731), began a reconnaissance mission in the Gulf of Tonkin. The purpose of the mission was to obtain information about the North Vietnamese coastal defense forces. Other similar US ships were involved in supporting South Vietnamese commando raids on the North Vietnamese coast during the same period.
Apparently mistaking the Maddox for South Vietnamese, three North Vietnamese torpedo boats launched a torpedo and machine gun attack on her. Responding immediately to the attack - and with the help of air support from the nearby carrier Ticonderoga - the MADDOX destroyed one of the attacking boats and damaged the other two. The MADDOX, suffering only superficial damage by a single 14.5-millimeter machine gun bullet retired to South Vietnamese waters, where she is joined by the C. TURNER JOY.
On August 3, GVN again attacks North Vietnam, the Rhon River estuary and the Vinh Sonh radar installation were bombarded under cover of darkness.
On August 4, a new DESOTO patrol to North Vietnam coast was launched, with the Maddox and the C. TURNER JOY. The latter got radar signals that they believed to be another attack by the North Vietnamese. For some two hours the ships fired on radar targets and maneuvered vigorously amid electronic and visual reports of torpedoes. Later, Captain John J. Herrick admitted that it was nothing more than an "overeager sonarman" who "was hearing ship's own propeller beat."
Though information obtained well after the fact indicates that there was actually no North Vietnamese attack that night, U.S. authorities were convinced at the time that one had taken place, and reacted by sending planes from the carriers Ticonderoga and Constellation to hit North Vietnamese torpedo boat bases and fuel facilities.
Squadron commander James Stockdale was one of the U.S. pilots flying overhead August 4th. In the 1990s Stockdale stated that he "had the best seat in the house to watch that event, and our destroyers were just shooting at phantom targets -- there were no PT boats there.... There was nothing there but black water and American fire power."
Lyndon Johnson, who was running for his first presidential election that year (having been instated into office without election after the assassination of JFK), launched retaliatory strikes and went on national television on August 4. Although the Maddox had been involved in providing support for South Vietnamese attacks at Hon Me and Hon Ngu, Johnson's Secretary of Defense, Robert McNamara, went before Congress and denied that the United States Navy was supporting South Vietnames military operations. He thus characterized the attack as "unprovoked". Despite the fact that there was no second attack, he also claimed before Congress that there was "unequivocable proof" of an "unprovoked" second attack against the Maddox. A year later, Johnson said in private "for all I know, our Navy was shooting at whales out there."
As a result of McNamara's testimony, on August 7, the Joint Resolution passed the House unanimously, and the Senate with only two 'no' votes: Senators Wayne Morse of Oregon, and Ernest Gruening of Alaska.
Both Johnson and President Richard Nixon used the Resolution as a justification for escalated involvement in Indochina. The Resolution was repealed in June of 1970 in a rebuke to the Nixon Administration's illegal bombing campaign Cambodia. The U.S. had already begun the process of withdrawing troops from the area in 1969, under a policy known as "Vietnamization", but didn't completely disengage from the region until 1973.