By August 1964, the United States Navy was supporting South Vietnam’s struggle against North Vietnam in two programs.
Operations Plan (OPLAN) 34 involved South Vietnamese naval and marine forces raiding North Vietnamese coastal installations with American advice and logistical support.
Operation DeSoto involved American naval vessels patrolling international waters off the coast of North Vietnam to observe the North Vietnamese Navy and probe the North Vietnamese radar capabilities by electronic surveillance. The destroyer USS Maddox patrolling 28 miles off the North Vietnamese coast as part of DeSoto came under attack by three North Vietnamese torpedo boats on August 2.
An OPLAN 34 raid against the torpedo boat base at Loc Chao had taken place on the night of July 31, and this probably precipitated the attack on the American destroyer. The Maddox fired warning shots, but the torpedo boats continued attacking by launching two torpedoes. These were avoided and fire from the destroyer damaged one of the torpedo boats.
Four Vought F-8E Crusaders, on patrol from the carrier USS Ticonderoga, came to aid the Maddox. The destroyer division commander on board the Maddox ordered the aircraft to attack the now-retiring torpedo boats. Several strafing runs with 20mm cannons and rocket attacks with 5-inch Zuni rockets resulted in the sinking of the damaged torpedo boat. The destroyer USS C. Turner Joy joined the Maddox and the carrier USS Constellation advanced to the area from Hong Kong. The two destroyers withdrew to an area 100 miles off the coast, and combat air patrols began.
On the evening of August 4, in poor weather conditions, the Maddox identified five high-speed radar contacts as North Vietnamese torpedo boats. The particulars of the engagement are rather confused, but American naval personnel were convinced they were being attacked, reporting several torpedo wakes while maneuvering in the darkness.
The Ticonderoga sent two Douglas A-l Sky-raiders to help out, and between the aircraft and destroyers two torpedo boats were reported destroyed and two damaged. President Johnson ordered retaliatory air strikes against four North Vietnamese torpedo boat bases on August 5.
Aircraft from the Ticonderoga and Constellation destroyed twenty-five boats and severely damaged the support facilities. The boats destroyed amounted to one-half of the total North Vietnamese torpedo boat strength. Two American aircraft were shot down by antiaircraft fire and two were damaged. An A-4 pilot became the first American prisoner of war in North Vietnam. On August 7, 1964, both houses of Congress passed the Gulf of Tonkin Resolution.