As dictated by the Geneva Conference of 1954, the partition of Vietnam was meant to be only temporary, pending national elections on July 20, 1956. Much like Korea, the agreement stipulated that the two military zones were to be separated by a temporary demarcation line (known as the Demilitarized Zone or DMZ).
Although the United States attended the Geneva Conference (1954), it refused to sign the Geneva Accords (1954). The Accords mandated, among other measures, a ceasefire line, intended to separate Vietnamese independence and French forces, and elections to determine the rulership of Vietnam on both sides of the line, within 2 years. It also forbade the political interference of other countries in the area, the creation of new governments without the stipulated elections, and foreign military presence. The United States promptly subverted all of the measures of the Accords at once when it installed anti-communist Ngo Dinh Diem as President of South Vietnam, and gave him military backing. By 1961, poor decisions by Diem, almost all against the counsel of his American advisors, including refusals to hold elections, and attacks on Buddhism (the majority religion in southern Vietnam), and other ethnic groups, had made him unpopular. In that year, a popular uprising began, headed by the National Liberation Front. The U.S. also began providing direct support to the South Vietnamese in the form of military and financial aid and military advisors, the number of which grew from 600 in 1961 to 16,000 by the end of John F. Kennedy's presidency in 1963.
The Gulf of Tonkin Incident occurred during the first year of the Johnson administration. While Kennedy had originally supported the policy of sending military advisors to Vietnam, he had begun to alter his thinking due to the military ineptitude of the Saigon government and its inability and unwillingness to make needed reforms. Shortly before his assassination in November 1963, he had begun limited recall of American forces. Johnson's views were likewise complex, but he had supported military escalation in Vietnam as a means to challenge the expansionist policies of the Soviet Union. The Cold War policy of containment was to be applied to prevent the "fall" of Southeast Asia under the precepts of the domino theory. After Kennedy's assassination, Johnson ordered in more American forces to support the Saigon government, beginning a protracted United States presence in Southeast Asia.
According to the U.S. Naval Institute[2], a highly classified program of covert attacks against the Democratic Republic of Vietnam (North Vietnam) known as Operation 34A, had begun under the Central Intelligence Agency (CIA) in 1961. In 1964 the program was transferred to the Defense Department and conducted by the Military Assistance Command, Vietnam Studies and Observations Group (SOG). For the maritime portion of the covert operation, Tjeld-class fast patrol boats had been purchased quietly from Norway and sent to South Vietnam. Although the crews of the boats were South Vietnamese naval personnel, approval of the plan came directly from Admiral U.S. Grant Sharp, Jr., CINCPAC in Honolulu. After the coastal attacks began, Hanoi lodged a complaint with the International Control Commission (ICC), which had been established in 1954 to oversee the terms of the Geneva Accords, but the U.S. denied any involvement. Four years later, Secretary of Defense Robert S. McNamara admitted to Congress that the U.S. ships had in fact been cooperating in the South Vietnamese attacks against the DRV.
