Lyndon B. Johnson (LBJ), as he took over the presidency after the death of Kennedy, initially did not consider Vietnam a priority and was more concerned with his " Great Society" and progressive social programs. Presidential aide Jack Valenti recalls, "Vietnam at the time was no bigger than a man's fist on the horizon. We hardly discussed it because it was not worth discussing."
On 24 November 1963, Johnson said, "the battle against communism... must be joined... with strength and determination." The pledge came at a time when Vietnam was deteriorating, especially in places like the Mekong Delta, because of the recent coup against Diem.
Johnson had reversed Kennedy's disengagement policy from Vietnam in withdrawing 1,000 troops by the end of 1963 (NSAM 263 on 11 Oct.) with his own NSAM 273 (26 Nov) to expand the war.
The military revolutionary council, meeting in lieu of a strong South Vietnamese leader, was made up of 12 members headed by General Duong Van Minh—whom Stanley Karnow, a journalist on the ground, later recalled as "a model of lethargy." Lodge, frustrated by the end of the year, cabled home about Minh: "Will he be strong enough to get on top of things?" His regime was overthrown in January 1964 by General Nguyen Khanh. However, there was persistent instability in the military as several coups—not all successful—occurred in a short space of time.
On 2 August 1964, the USS Maddox, on an intelligence mission along North Vietnam's coast, allegedly fired upon and damaged several torpedo boats that has been stalking it in the Gulf of Tonkin
A second attack was reported two days later on the USS Turner Joy and Maddox in the same area. The circumstances of the attack were murky. Lyndon Johnson commented to Undersecretary of State George Ball that "those sailors out there may have been shooting at flying fish."
The second attack led to retaliatory air strikes, prompted Congress to approve the Gulf of Tonkin Resolution, and gave the president power to conduct military operations in Southeast Asia without declaring war. In the same month, Johnson pledged that he was not "... committing American boys to fighting a war that I think ought to be fought by the boys of Asia to help protect their own land."
An undated NSA publication declassified in 2005, however, revealed that there was no attack on 4 August. It had already been called into question long before this. " Gulf of Tonkin incident", writes Louise Gerdes, "is an oft-cited example of the way in which Johnson misled the American people to gain support for his foreign policy in Vietnam." George C. Herring argues, however, that McNamara and the Pentagon "did not knowingly lie about the alleged attacks, but they were obviously in a mood to retaliate and they seem to have selected from the evidence available to them those parts that confirmed what they wanted to believe."
"From a strength of approximately 5,000 at the start of 1959 the Viet Cong's ranks grew to about 100,000 at the end of 1964...Between 1961 and 1964 the Army's strength rose from about 850,000 to nearly a million men. "The numbers for U.S. troops deployed to Vietnam during the same period were quite different; 2,000 in 1961, rising rapidly to 16,500 in 1964.
The National Security Council recommended a three-stage escalation of the bombing of North Vietnam. On 2 March 1965, following an attack on a U.S. Marine barracks at Pleiku, Operation Flaming Dart (initiated when Soviet Premier Alexei Kosygin was at a state visit to North Vietnam), Operation Rolling Thunder and Operation Arc Light commenced. The bombing campaign, which ultimately lasted three years, was intended to force North Vietnam to cease its support for the National Front for the Liberation of South Vietnam (NLF) by threatening to destroy North Vietnam's air defenses and industrial infrastructure. As well, it was aimed at bolstering the morale of the South Vietnamese. Between March 1965 and November 1968, "Rolling Thunder" deluged the north with a million tons of missiles, rockets and bombs.
Bombing was not restricted to North Vietnam. Other aerial campaigns, such as Operation Commando Hunt, targeted different parts of the NLF and VPA infrastructure. These included the Ho Chi Minh trail, which ran through Laos and Cambodia. The objective of forcing North Vietnam to stop its support for the NLF, however, was never reached. As one officer noted "this is a political war and it calls for discriminate killing. The best weapon... would be a knife... The worst is an airplane." The Chief of Staff of the United States Air Force Curtis LeMay, however, had long advocated saturation bombing in Vietnam and wrote of the Communists that "we're going to bomb them back into the Stone Age".
After several attacks upon them, it was decided that U.S. Air Force bases needed more protection. The South Vietnamese military seemed incapable of providing security. On 8 March 1965, 3,500 U.S. Marines were dispatched to South Vietnam. This marked the beginning of the American ground war. U.S. public opinion overwhelmingly supported the deployment.
In a statement similar to that made to the French almost two decades earlier, Ho Chi Minh warned that if the Americans "want to make war for twenty years then we shall make war for twenty years. If they want to make peace, we shall make peace and invite them to afternoon tea." As former First Deputy Foreign Minister Tran Quang Co has noted, the primary goal of the war was to reunify Vietnam and secure its independence. The policy of the Democratic Republic of Vietnam (DRV) was not to topple other non-communist governments in South East Asia.
The Marines' assignment was defensive. The initial deployment of 3,500 in March was increased to nearly 200,000 by December. The U.S. military had long been schooled in offensive warfare. Regardless of political policies, U.S. commanders were institutionally and psychologically unsuited to a defensive mission. In December, ARVN forces suffered heavy losses at the Battle of Bình Giã, in a battle that both sides viewed as a watershed. Previously communist forces had utilized hit-and-run guerrilla tactics, however at Binh Gia they had successfully defeated a strong ARVN force in conventional warfare. Tellingly, South Vietnamese forces were again defeated in June, at the Battle of Đồng Xoài.
Desertion rates were increasing, and morale plummeted. General William Westmoreland informed Admiral U.S. Grant Sharp, Jr., commander of U.S. Pacific forces, that the situation was critical. He said, "I am convinced that U.S. troops with their energy, mobility, and firepower can successfully take the fight to the NLF [National Front for the Liberation of South Vietnam]." With this recommendation, Westmoreland was advocating an aggressive departure from America's defensive posture and the sidelining of the South Vietnamese. By ignoring ARVN units, the U.S. commitment became open-ended. Westmoreland outlined a three-point plan to win the war:
The one-year tour of duty deprived units of experienced leadership. As one observer noted "we were not in Vietnam for 10 years, but for one year 10 times." As a result, training programs were shortened.
South Vietnam was inundated with manufactured goods. As Stanley Karnow writes, "the main PX [Post Exchange], located in the Saigon suburb of Cholon, was only slightly smaller than the New York Bloomingdale's..." The American buildup transformed the economy and had a profound impact on South Vietnamese society. A huge surge in corruption was witnessed.