Tensions between the U.S. and North Vietnam were already quite high without the Gulf of Tonkin Incident. From the late 1950s through the early 1960s the U.S. sent spies and saboteurs to North Vietnam. At the end of 1963 North Vietnam decided to increase military action in South Vietnam. (Moise 45)
By early 1964 the general consensus was that the U.S. was losing the war and that whoever was in charge of the South Vietnamese government would fall to the communists quickly. Consequently, the U.S. military advocates bombing North Vietnam. Republican politicians in the U.S. agreed; all this prior to the Gulf of Tonkin incidents. The Army of the Republic of Vietnam and the South Vietnamese Navy were considered inept. It was clear to the administration that U.S. involvement would have to increase soon. “The war was being lost in slow motion.” (Moise 38, 45) In addition, U.S. and South Vietnamese intelligence was weak. (Moise 47)
Nevertheless, William Bundy said that LBJ “would not make any new major decision . . . at least until after the election.” (Moise 44; see footnote) In addition, General Khanh told Secretary of Defense McNamara in May 1964 that he wanted to solidify his position as leader of South Vietnam before attacking North Vietnam he soon after told Secretary of State Dean Rusk that an invasion of North Vietnam would boost South Vietnamese “morale."(Moise 29-42 passim.)
The Gulf of Tonkin incident and resulting resolution remain as controversial as they were at the time. Most people now accept it as a ruse to begin American combat in Viet Nam the original opposition was noticed by how few opposed. Only two US Senators voiced concern and voted no on the resolution. Today only the far-right fringes of politics believe that the North Vietnamese attacked two US ships on August 4, 1964 and view the resulting resolution as a declaration of war.
I have included contemporary writings and media accounts of the incidents as well as the first research done after the resolution.