In 1965, the United States under Lyndon B. Johnson entered large-scale war in Vietnam. It did so incrementally, over a period of several months in the first half of the year. The contingency planning for war, however, went back considerably further. Already in the spring of 1964, Johnson administration insiders had agreed that the present policy--which limited overt U.S. involvement to funding, equipping, and advising the South Vietnamese government in its struggle against a Hanoi-directed insurgency--no longer had a reasonable chance of being successful. Absent a more active American intervention, involving either air and naval attacks on the North or ground troops in the South, Communist-led forces would take over in South Vietnam, probably within months, whether by way of a military victory, a collapse of the Saigon regime, or a diplomatic settlement among the Vietnamese. (1)
American planners hoped any escalation could be delayed until after the 1964 presidential election. On November 3, 1964, the very day voters gave Johnson a landslide victory over Republican Barry Goldwater, senior officials commenced secret deliberations concerning how to stave off a South Vietnamese defeat. By early December, the president and his aides had decided to implement a two-phase escalation of the fighting. The first would involve "armed reconnaissance strikes" against infiltration routes in Laos--part of the so-called Ho Chi Minh Trail that carried men and materiel into the South-as well as retaliatory air strikes against North Vietnam in the event of a major Vietcong attack. The second phase would see "graduated military pressure" against the North, in the form of aerial bombing, and, almost certainly, the dispatch of U.S. ground troops to the South. Phase one would begin as soon as possible; phase two would come later, some time after 30 days.
In February 1965, in response to Vietcong attacks on American installations in South Vietnam that killed 32 Americans, President Johnson ordered Operation Rolling Thunder, a bombing program against North Vietnam that continued, more or less uninterrupted, until October 1968. Then, on March 8, the first U.S. combat battalions came ashore near Danang. More troops soon followed, and in April, Johnson authorized them to engage in offensive operations within 50 miles of their base area. By mid-May, the total number of American forces in Vietnam had risen to 47,000 and was still climbing to the new ceiling of 82,000.
Then, in late July 1965, following several days of meetings among top civilian and military officials, Johnson approved the immediate deployment of an additional 50,000 U.S. troops and privately agreed to send another 50,000 before the end of the year. He also authorized General William Westmoreland, the commander of American forces, to adopt an aggressive search-and-destroy strategy and to increase dramatically the bombing of North Vietnam. Students of the war have tended to attach great importance to these "July decisions," seeing in them the crossover point to major war. But by then the war was already under way. The air campaign had begun months before, and sizable numbers of combat troops were already on the ground and engaging in offensive operations. By July, Johnson's options had narrowed drastically. His personal credibility, as well as the credibility of the Democratic Party and of the United States internationally, was on the line to a much greater degree than it had been before the beginning of March.
On some level, Johnson knew by July that he was hemmed in. For many weeks, he had been telling his wife Lady Bird and others that he felt trapped by his Vietnam commitment. He had said the same thing on occasion already in 1964, to be sure, but now the claim had more legitimacy. Maybe that helps explain why, in the spring and early summer weeks of 1965, he made little effort to break out of the trap, to order a full-scale reevaluation of policy including serious exploration of possible alternatives to a military solution. …