Unlike conventional wars, the war in Vietnam had no defined front lines. Much of it consisted of hit-and-run attacks, with the guerrillas striking at government outposts and retreating into the jungle. In the early 1960s some North Vietnamese troops, however, began to infiltrate into South Vietnam to help the Vietcong, and supplies sent to Hanoi from the USSR and China were sent south down the so-called Ho Chi Minh Trail. The war began to escalate in the first week of August 1964, when North Vietnamese torpedo boats were reported to have attacked two US destroyers in the Gulf of Tonkin. Acting on the resolution passed on August 7 by the US Senate (the so-called Tonkin Gulf Resolution), authorizing increased military involvement, President Lyndon B. Johnson ordered jets to South Vietnam and the retaliatory bombing of military targets in North Vietnam. From 1964 to 1968 General William C. Westmoreland was commander of US forces in South Vietnam; he was replaced in 1968 by General Creighton Abrams.
In February 1965, US planes began regular bombing raids over North Vietnam. A halt was ordered in May in the hope of initiating peace talks, but when North Vietnam rejected all negotiations, the bombings were resumed. In the meantime, the United States continued to build up its troop strength in South Vietnam. On March 6, 1965, a brigade of American marines landed at Ðà Nang, south of the demilitarized zone (DMZ) that had originally been set up at the time of partition. The marines, the first US combat ground-force units to serve in the country, brought the number in the US military forces in Vietnam to some 27,000. By the end of the year American combat strength was nearly 200,000.
... during the first Indochina War. When the war ended the country was split into two creating North and South Vietnam. North Vietnam soon came under ... and fifty thousand sorties per year were flying and bombing things civilian casualties were really hard to avoid. These ... a serious defeat to North Vietnamese forces. After the battle the North Vietnamese and the NLF forces decided to change strategies. ...
While continuing the military build-up in Vietnam, the United States made another attempt to end the war. In December 1965, President Johnson again halted the bombing of North Vietnam in an effort to achieve a peaceful settlement. Again he was unsuccessful, and the raids were resumed. In June 1966, US planes began bombing major installations near Hanoi and the neighbouring port of Haiphong, both of which had hitherto been spared.
In October 1966, government representatives from the United States, Australia, New Zealand, Thailand, South Korea, and the Philippines—all of which had contributed troops to South Vietnam—met in Manila and pledged their withdrawal within six months after North Vietnam abandoned the war. The offer was rejected by North Vietnam. In June 1967, President Johnson met with Soviet Premier Aleksey N. Kosygin and sought his help in bringing Hanoi to the peace table. The war, however, dragged on.
Two months after the meeting, President Johnson announced that US forces in Vietnam would be further increased to 525,000 by 1968. At the same time, US planes extended their bombings of North Vietnam to within 16 km (10 mi) of the Chinese border. Shortly thereafter, President Johnson again offered to stop the bombardment of North Vietnam provided peace talks would follow. As in the past, Hanoi rejected the offer.
The war continued, and casualty figures rose. In November 1967, the Pentagon announced that total US casualties in Vietnam since the beginning of 1961 had reached 15,058 killed and 109,527 wounded. The mounting toll was accompanied by a growing call within the United States for an end to the war, the cost of which, apart from the loss of life, was estimated by the president at $25 billion per year.