On August 2, 1964, USS Maddox, an American destroyer, was attacked in the Gulf of Tonkin by three North Vietnamese torpedo boats while conducting an intelligence mission. A second attack seemed have occurred two days later, though the reports were sketchy (It now appears that there was no second attack). This second “attack” led to US air strikes against North Vietnam and the passage of the Southeast Asia (Gulf of Tonkin) Resolution by Congress. This resolution permitted the president to conduct military operations in the region without a formal declaration of war and became the legal justification for escalating the conflict.
In retribution for the incident in the Gulf of Tonkin, President Lyndon Johnson issued orders for the systematic bombing of North Vietnam, targeting its air defenses, industrial sites, and transportation infrastructure. Beginning on March 2, 1965, and known as Operation Rolling Thunder, the bombing campaign would last over three years and would drop an average of 800 tons of bombs a day on the north. To protect US airbases in South Vietnam, 3,500 Marines were deployed that same month, becoming the first ground forces committed to the conflict.
By April 1965, Johnson had sent the first 60,000 American troops to Vietnam. The number would escalate to 536,100 by the end of 1968. In the summer of 1965, under the command of General William Westmoreland, US forces executed their first major offensive operations against the Viet Cong and scored victories around Chu Lai (Operation Starlite) and in the Ia Drang Valley. This latter campaign was largely fought by the 1st Air Cavalry Division which pioneered the use of helicopters for high speed mobility on the battlefield.
Learning from these defeats, the Viet Cong seldom again engaged American forces in conventional, pitched battles preferring instead to resort to hit and run attacks and ambushes. Over the next three years, American forces focused on searching and destroying Viet Cong and North Vietnamese units operating in the south. Frequently mounting large scale sweeps such as Operations Attleboro, Cedar Falls, and Junction City, American and ARVN forces captured large amounts of weapons and supplies but rarely engagd large formations of the enemy.
Political Situation in South Vietnam
In Saigon, the political situation began to calm in 1967, with the rise of Nguyen Van Theiu to the head of the South Vietnamese government. Theiu’s ascent to the presidency stabilized the government and ended a long series of military juntas that had administered the country since Diem’s removal. Despite this, the Americanization of the war clearly showed that the South Vietnamese were incapable of defending the country on their own.