On 7 August 1964, Johnson secured almost unanimous consent from Congress (414–0 in the House; 88–2 in the Senate) for his Gulf of Tonkin Resolution, which became the principal legislative basis for all subsequent military deployment in Southeast Asia.

On 7 August 1964, Johnson secured almost unanimous consent from Congress (414–0 in the House; 88–2 in the Senate) for his Gulf of Tonkin Resolution, which became the principal legislative basis for all subsequent military deployment in Southeast Asia.

Flying low over the jungle, an A-1 Skyraider drops 500-pound bombs on a Viet Cong position below as smoke rises from a previous pass at the target, on December 26, 1964.

Johnson’s decisive but restrained response to the Gulf of Tonkin incidents helped him win the 1964 election, but Saigon’s prospects continued to decline. The president wanted to concentrate on his ambitious domestic program, the Great Society, but his political instincts told him that his leadership would be damaged fatally if America’s client state in South Vietnam succumbed. Instability mounted in South Vietnam as rival military and civilian factions vied for power and as Vietcong strength grew.

A consensus formed among Johnson’s advisers that the United States would have to initiate air warfare against North Vietnam. Bombing could boost Saigon’s morale and might persuade the North to cease its support of the insurgency.

The Joint Chiefs of Staff (JCS) favored a massive bombing campaign, but civilians in the State and Defense Departments preferred a gradual escalation.

Partially covered, a dying Viet Cong guerrilla raises his hands as South Vietnamese Marines search palm groves near Long Binh in the Mekong Delta, on February 27, 1964. The guerrilla died in a foxhole following a battle between a battalion of South Vietnamese Marines and a unit of Viet Cong.

In 1965, U.S. aircraft flew 25,000 sorties against North Vietnam, and that number grew to 79,000 in 1966 and 108,000 in 1967. In 1967 annual bombing tonnage reached almost a quarter million. Targets expanded to include the Ho Chi Minh Trail in Laos and factories, farms, and railroads in North Vietnam.

From the beginning of the bombing, American strategists debated the effectiveness of airpower in defeating a political insurgency in a predominantly agricultural country. Despite the American bombs, dollars, and military advisers, the Vietcong continued to inflict heavy casualties on the ARVN, and the political situation in Saigon grew worse.

As U.S. “Eagle Flight” helicopters hover overhead, South Vietnamese troops wade through a rice paddy in Long An province during operations against Viet Cong guerrillas in the Mekong Delta, in December of 1964. The “Eagle Flight” choppers were loaded with Vietnamese airborne troops who were dropped in to support ground forces at the first sign of enemy contact.

To stave off defeat, the JCS endorsed Westmoreland’s request for 150,000 U.S. troops to take the ground offensive in the South. When McNamara concurred, Johnson decided to commit the forces. The buildup of formal U.S. military units had begun on 8 March 1965, when two battalions of Marines landed at Da Nang.