US involvement in Vietnam 1954-1965
The Origins: Vietnam and the End of French Rule
Vietnam had been part of French Indochina since the nineteenth century. Following the Second World War, the Vietnamese independence movement, the Viet Minh, fought the French for independence. On 7 May 1954, the French garrison at Dien Bien Phu surrendered after a prolonged siege by Viet Minh forces. The defeat ended French rule and led directly to the Geneva Conference.
The Geneva Accords of July 1954 divided Vietnam temporarily at the 17th parallel: the communist Democratic Republic of Vietnam under Ho Chi Minh in the north, and the non-communist Republic of Vietnam in the south. Nationwide elections were to be held in 1956. The USA and the South Vietnamese government refused to permit them, fearing Ho Chi Minh would win.
The Geneva Accords (July 1954) divided Vietnam at the 17th parallel and promised nationwide elections by 1956. The USA and South Vietnam refused to allow the elections, fearing a communist victory. This refusal undermined the legitimacy of the South Vietnamese government and strengthened the case for armed reunification from the North.
US Involvement under Eisenhower: Advisers and the Domino Theory
President Eisenhower articulated the domino theory in April 1954: if one country fell to communism, neighbouring states would follow like a row of falling dominoes. To prevent this, Eisenhower backed South Vietnamese President Ngo Dinh Diem, providing economic aid and military advisers. By 1963 there were approximately 16,000 US military advisers in South Vietnam.
Diem’s government was authoritarian, corrupt and deeply unpopular in rural areas. His anti-Buddhist policies in 1963 triggered large-scale protests. In November 1963, Diem was overthrown and killed in a CIA-backed coup. Three weeks later, President Kennedy was assassinated in Dallas. Lyndon B. Johnson inherited a deteriorating situation.
In December 1960, communist and anti-Diem opponents in the South formed the National Liberation Front (NLF), known to their opponents as the Vietcong. The NLF combined guerrilla tactics with a political programme offering land reform and an end to foreign influence. American officials portrayed the NLF as puppets of Hanoi; many historians argue the NLF had significant independent roots in southern grievances against the Diem regime.
The NLF’s growing strength and the instability of successive South Vietnamese governments after Diem’s assassination intensified pressure on Johnson to escalate. Robert McNamara, Defense Secretary, and the Joint Chiefs urged more direct US action to prevent South Vietnam’s collapse.
The Gulf of Tonkin and Escalation 1964–1965
In August 1964 the USS Maddox reported being attacked by North Vietnamese torpedo boats in the Gulf of Tonkin. A second alleged attack two days later was almost certainly a radar error, but Johnson used both incidents to persuade Congress to pass the Gulf of Tonkin Resolution, granting him near-unlimited authority to escalate US involvement in Vietnam without a formal declaration of war.
In March 1965 the USA launched Operation Rolling Thunder, a sustained bombing campaign against North Vietnam. The same month, the first US combat troops — 3,500 Marines — landed at Da Nang. The USA had moved from providing advisers to fighting a ground war. US troop numbers rose from 23,000 in 1964 to 184,000 by the end of 1965.
The Gulf of Tonkin Resolution (August 1964) was based partly on a genuine attack on USS Maddox and partly on a second incident that was almost certainly a radar error. It gave the President authority to use military force in Southeast Asia without a formal declaration of war — and was later cited as an example of how incomplete information led to escalation.
The domino theory gave US policy-makers a framework for justifying intervention in any country that appeared at risk of communist takeover. Vietnam fitted this framework: if South Vietnam fell, Laos, Cambodia, Thailand and beyond might follow. Critics of the theory, including Senator William Fulbright, whose Senate Foreign Relations Committee hearings in 1966 challenged the administration’s assumptions, argued that communist movements were often nationalist rather than Soviet-directed. The distinction between genuine communism and anti-colonial nationalism was one the US government was slow to make.
The USA also faced a credibility argument: having pledged to defend South Korea in the early 1950s, abandoning South Vietnam would signal to allies and adversaries alike that American security guarantees could not be trusted. This credibility logic trapped successive administrations in a conflict whose military solution remained elusive. The escalation from advisers (Eisenhower) to ground troops (Johnson) followed a logic that was coherent within containment theory but increasingly difficult to sustain against a guerrilla opponent.