The Vietnam War: Origins and Tactics

From French defeat to a divided Vietnam, 1954

US involvement in Vietnam grew gradually: support for an anti-communist government developed into a major American war. To understand this change, we need to connect Vietnam’s struggle for independence with the wider Cold War.

Vietnam had been under French colonial rule. The Viet Minh, led by Ho Chi Minh, fought for independence and had strong communist connections. The USA had already helped finance France’s war against them. American leaders viewed the struggle not simply as a colonial conflict, but as a possible advance for communism.

In 1954, the Viet Minh defeated the French at Dien Bien Phu. The Geneva settlement temporarily divided Vietnam at the 17th parallel. Ho Chi Minh’s communist government controlled the North, while a separate regime governed the South. Nationwide elections were planned for 1956 to reunify the country. The division was therefore intended to be temporary, not a permanent settlement creating two countries.

Why the USA supported South Vietnam

The USA followed containment: preventing communism from spreading further. President Dwight D. Eisenhower also believed in the domino theory. He argued that if Vietnam became communist, other countries in South-East Asia might follow, like falling dominoes. Communist victory in China in 1949 and the conflict in Korea strengthened American fears about communist expansion in Asia.

This was an American prediction, not proof that neighbouring countries would inevitably become communist. Nevertheless, it made Vietnam seem important to the balance of power in the Cold War, rather than just a distant local conflict.

The USA supported the anti-communist South Vietnamese leader Ngo Dinh Diem. Ho Chi Minh appeared likely to win nationwide elections, so the Americans backed Diem’s refusal to hold them. After a fraudulent vote in the South in 1955, Diem removed Bao Dai and declared himself president. The planned reunification elections did not take place in 1956.

Eisenhower supplied Diem with money, weapons, vehicles and military advisers rather than sending a regular American ground combat army. The aim was to build a South Vietnam strong enough to resist communism. However, Diem’s government was corrupt and repressive. Its treatment of opponents and failure to address rural grievances alienated farmers, students and Buddhists. Supporting an anti-communist leader did not necessarily produce a popular or democratic government.

Kennedy: more assistance, but a weaker ally

By 1960, the National Liberation Front (NLF) had been established to oppose Diem. Its guerrilla fighters were known as the Vietcong. North Vietnam supported the insurgency, while discontent with Diem helped it gain support within South Vietnam.

President John F. Kennedy, who took office in 1961, also believed that South Vietnam must not fall to communism. He increased financial assistance, military training and helicopter support. By November 1963, about 16,000 US military personnel were in Vietnam. Their involvement included training South Vietnamese forces and supporting air operations: this was more than simply sending money, although Kennedy had not deployed the regular ground combat forces later sent by Johnson.

Kennedy also supported Diem’s Strategic Hamlet Programme. Peasants were moved into fortified settlements to separate them from the Vietcong and prevent them supplying guerrillas with food and information. Forced relocation disrupted people’s lives and was deeply unpopular. Instead of securing loyalty to Diem, it could increase support for his opponents.

Diem’s failures created a dilemma for the USA. More American assistance had not made his government secure, but abandoning South Vietnam seemed to risk a communist victory. On 2 November 1963, South Vietnamese military officers overthrew and killed Diem, with the Kennedy administration’s tacit approval. His removal did not bring stability: subsequent governments remained weak, and South Vietnamese forces continued to suffer military setbacks.

Johnson and the move to direct war, 1964–65

Lyndon B. Johnson became president after Kennedy’s assassination in November 1963. He inherited an unstable South Vietnam and an existing American commitment to defend it. His administration increasingly regarded greater US military involvement as the answer to the South’s weaknesses.

In August 1964, American destroyers in the Gulf of Tonkin reported attacks by North Vietnamese patrol boats. An attack was reported on 2 August, followed by a second reported attack on 4 August. Doubts later emerged over whether the second attack had occurred. The distinction matters because Johnson used the reported incidents to justify stronger action.

On 7 August 1964, Congress passed the Gulf of Tonkin Resolution. It authorised Johnson to take measures he considered necessary to retaliate and maintain security in South-East Asia. This gave him broad authority to escalate the war without a formal declaration of war.

In 1965, Johnson launched sustained bombing of North Vietnam through Operation Rolling Thunder and authorised the deployment of regular US ground combat troops. The USA was now taking on a direct fighting role rather than primarily supporting South Vietnamese forces.

The origins of this involvement therefore form a connected chain: fear of communist expansion encouraged support for Diem; Diem’s failures prompted greater assistance; continuing instability encouraged Johnson to escalate; and the Tonkin incidents provided the immediate justification for doing so.

Two different ways of fighting

The United States possessed far greater wealth, firepower and military technology than the Vietcong. American forces tried to turn those advantages into victory through bombing, helicopter operations and the destruction of vegetation that concealed their opponents.

The Vietcong used guerrilla warfare: hiding, launching small surprise attacks and avoiding large battles where American firepower would be most effective. This made the war a struggle not simply to destroy an enemy army, but to find fighters, interrupt their supplies and maintain control of the countryside.

Bombing: Operation Rolling Thunder

Operation Rolling Thunder lasted from March 1965 to November 1968. The Americans aimed to destroy factories producing weapons and supplies in North Vietnam and prevent supplies reaching the Vietcong along the Ho Chi Minh Trail. They also hoped that sustained bombing would pressure the North Vietnamese government to weaken its support for the war in the South.

Bombing damaged factories and other targets, but destroying production sites did not end the supply of weapons. North Vietnam continued to receive supplies from China and the USSR, while supplies continued to move along the trail. The campaign therefore caused substantial destruction without achieving its central aim of cutting off the Vietcong.

There were also serious consequences beyond the damaged targets. American aircraft were shot down, while bombing killed large numbers of Vietnamese civilians. Civilian deaths damaged the USA’s reputation: its technological strength could appear destructive rather than protective.

Helicopters and search-and-destroy operations

Helicopters enabled American troops to move quickly into areas where Vietcong activity was suspected. During search-and-destroy operations, soldiers searched villages and surrounding countryside for fighters, hiding places and supplies. Villages could be destroyed and their inhabitants forcibly relocated.

Speed of movement did not guarantee that the enemy would be found. The sound of approaching helicopters warned Vietcong fighters, who could hide before troops arrived. Once American soldiers left their helicopters, they remained vulnerable to ambushes and booby traps. Fighters could also return after the Americans withdrew from an area.

Operation Cedar Falls, launched in January 1967 near Saigon, shows the difference between immediate gains and lasting success. Around 30,000 American and Army of the Republic of Vietnam soldiers swept an area containing Vietcong tunnels and supply depots. Villagers were forcibly removed, tunnels were destroyed, supplies were captured and around 700 guerrillas were killed. However, most Vietcong fighters escaped, and the operation did not greatly reduce their ability to fight or control the area.

For civilians, search-and-destroy operations meant ruined homes, displacement and insecurity. These consequences turned many South Vietnamese people against the Americans. Television footage of burning villages also damaged the USA’s reputation. A tactic could therefore secure a military gain while weakening support among the people whose cooperation mattered.

Burning targets and removing jungle cover

American forces used napalm, a highly flammable jelly, to burn targets. When a napalm bomb exploded, burning material spread over an area and stuck to whatever it struck. It was difficult to extinguish and caused severe injuries and civilian deaths.

Herbicides served a different purpose. Operation Ranch Hand, which ran from 1962 to 1971, involved spraying chemicals such as Agent Orange and Agent Blue over vegetation and crops. The aim was to remove the jungle cover that hid Vietcong fighters and destroy crops that fed them.

These methods attacked the environment on which guerrilla warfare depended, but their effects extended far beyond fighters. Destroyed crops harmed civilian livelihoods, while chemical contamination had lasting health consequences, including cancers, birth defects and miscarriages. The consequences of a tactic must therefore be judged over time, not only at the moment of an attack.

How the Vietcong reduced American advantages

The jungle provided cover for fighters and concealed ambushes and booby traps. Rather than confronting a large American force directly, guerrillas could attack unexpectedly and then hide. Booby traps caused deaths and injuries while making movement dangerous even when no enemy was visible.

The Vietcong also built extensive tunnel networks. These provided hiding places and shelter from bombing, helping fighters survive attacks from a much more powerful opponent. Meanwhile, supplies arriving along the Ho Chi Minh Trail helped sustain their operations despite American attempts to interrupt them.

Relations with villagers were important too. Supporting farmers could encourage cooperation, while brutal punishment of people who collaborated with the enemy discouraged others from doing so. Cooperation therefore did not always mean freely given support: fear could also help the Vietcong maintain influence.

Judging effectiveness and consequences

American tactics could destroy factories, tunnels and supplies, and kill guerrilla fighters. However, these achievements did not necessarily prevent supplies arriving, stop fighters returning or produce lasting control. Civilian suffering could also undermine the political value of military gains.

Vietcong tactics were effective at limiting the advantages of American technology. Concealment, surprise attacks, tunnels and continued supplies helped them remain active against a stronger force. Their methods nevertheless involved violence and intimidation as well as support from civilians. A balanced judgement separates military effectiveness, control of an area and consequences for people.