The Tonkin Gulf incidents were major events that prompted the Tonkin Gulf Resolution. On 31 July 1964 the U.S. Navy destoyer Maddox started a reconnaissance cruise off the coast of North Vietnam. It carried extra radio gear andm personnel to monitor Democratic Republic of Vietnam (DRV) radio communications but was not a true electronic espionage vessel.
Around the time of the cruise, the United States scheduled an unusually intense string of covert operations (DeSoto Missions) against the North Vietnamese coast. These were carried out by relatively small vessels having Vietnamese crews but operating under U.S. orders. Based near Da Nang, they were part of Operation Plan 34A (OPLAN 34A). Two islands off the coast of North Vietnam were to be attacked on the night of 30-31 July; two points on the North Vietnamese mainland were to be shelled on the night of 3-4 August; on island was to be shelled, and one fishing boat crew was to be seized for interrogation, on 5 August. One of the Maddox’s main missions was to learn about North Vietnamese coastal defenses, and it apparently was believed that more would be learned if those defenses were in an aroused state.
On the evening of 1 August the Maddox approached within gun range of Hon Me (one of two islands shelled by OPLAN 34A vessels on 30-31 July), and the costal defense forces became more aroused then the Americans had planned on. On the afternoon of 2 August, three DVR torpedo boats unsuccessfully attacked the destroyer. President Johnson was annoyed that the torpedo boats had not been sunk, but he decided not to order any further retaliation, partly because he had reason to believe that the attack had not been a deliberate decision by the Hanoi government.
On 3 August the Maddox and another destroyer, the C. Turner Joy, resumed the patrol in the Gulf of Tonkin, operationg under more cautious orders then those of 31 July. The destroyers were kept farther from the North Vietnamese coast and completely out of the extreme northern section of the Gulf, limitations that seriously reduced the destoyers’ ability to collect useful information.
Patrol commander Capt. John Herrick thought that another North Vietnamese attack was likely. For about two hours on the stormy night of 4 August, such an attack seemed to be in progress, but the situation was confused. The C. Turner Joy fired at objects on its radar screens that were unseen to the Maddox’s radar, while the Maddox’s sonar equipment picked up sounds (interpreted to be DRV torpedo boat motors) that could not be heard by the C. Turner Joy’s sonar equipment. Discussions are still held today as to wether an attack took place or not.
President Johnson, believing an attack had occured, ordered retalitory airstrikes (Operation Pierce Arrow), which were carried out on the afternoon of 5 August. He also asked for and quickly obtained a congressional resolution (the Tonkin Gulf Resolution, passed almost unanimously) authorizing him to do whatever was necessary to deal with Communist aggression in Vietnam.