America’s involvement in the war was caused by the Cold War background and anti-communist foreign policies that America desired to maintain which resulted in a drive to restrict the looming threat of the expansion of the Soviet sphere of communism. The US saw Vietnam as a key battle in their policy of containment and the domino theory stipulated by Eisenhower in 1954 was used as grounds for action. The falling ‘domino’ principle speculated that if one land in a region came under the influence of communism then the surrounding countries would succumb to this evil ideology in a domino effect. After the fall of China in 1949 America expected a chain reaction to spread to Vietnam and beyond. In the case of Vietnam they believed that if it fell to communism its Indo-China neighbours; Laos, Cambodia and Thailand would soon follow. America’s commitment to her desire for capitalist countries to remain free and uphold democracy resulted in the adoption of the Truman doctrine which helped to financially restore European countries and was a strategy of containment against the Soviet Union and the expansion of communism. Consequently the US felt obligated to support South Vietnam in their struggle against the communist North to whom their Cold War enemy: the USSR supplied with; medical supplies, arms, tanks, planes, helicopters, artillery, anti-aircraft missiles and other military equipment.
America had been historically involved in Vietnam for a large period of time which made it easy for their participation to escalate until they became so entangled that war was the inevitable outcome. The US had supported France in their re-occupation of Vietnam (despite their objects to colonisation) due to their strong anti-communist ideology. Therefore they felt they had to fill the void when France pulled-out of Vietnam in 1955-56 (after the peace accords which had divided Vietnam in half at the 17th parallel) to prevent Ho Chi Minh from unifying Vietnam under communist rule. As a result, starting in 1955 they sent military advisors to assist the South Vietnamese Army and this number augmented and their involvement escalated. As a result of involvement expanding incrementally they supported and installed a puppet government led by Ngo Dinh Diem which became another basis for their future militarial role in the war in Vietnam.
Diem’s government were corrupt and deceitful, and failed to gain the favour of the South Vietnamese people, as a result there was a rapid spread of sympathy towards the Vietminh and in 1959 the Vietcong was formed which consequently meant that the USA had to enhance their support to stop South Vietnam falling to communism. Diem’s catholic government were regarded even less because the religious composition of the country estimated the Buddhist majority to be between 70 and 90 percent. They also used unfavourable tactics such as election rigging, for instance in Diem’s election in 1955, he won with an extremely unrealistic 98.2 per cent of the vote in fact in Saigon there were 450,000 people entitled to vote yet 605,000 managed to cast their vote for Diem. The way that democracy, the fulfilment of promises and the reliability of the government (all things that the US desired to promote and uphold in South Vietnam) were being demeaned gave the Vietminh regime additional attraction. For instance Diem did not carry out land reforms which created resentment among the peasant populace because land was taken from peasant farmers and only 13 percent of the South Vietnam's land was redistributed and by the end of his regime, only 10 percent of the tenants had received any land, at a high cost. In fact at the end of Diem's rule, 10 percent of the population owned 55 percent of the land and this embittered the South Vietnamese peasants and made the Vietminh’s act of distributing land to peasants seem admirable. The regime's relations with the U.S. worsened during 1963, as well as heightening discontent among South Vietnam's Buddhist majority. Diem pursued pro-Catholic policies that antagonized many Buddhists; US aid was disproportionately distributed to Catholic majority villages and the government was regarded as being biased towards Catholics in public service and military promotions, as well as the allocation of land, business favours and tax concessions. After the incident in Hue in May 1963 where the police attempted to disperse the crowd using weaponry, the United States came to the realisation that Diem could not establish control. As a result of this awareness, the government of the US financed the Army of the Republic of Vietnam (ARVN) to overthrow him in a coup (despite having channelled substantial funds into his former regime). However there was no guarantee that the ARVN would be an improvement on Diem’s rule and the US were brought to the conclusion that they could not deal with the rapid growth of the Vietcong without further American input. The failure of Diem’s government meant that the United States had to support South Vietnam more substantially and this propping up escalated until war was unavoidable.
Lyndon Baines Johnson who succeeded to the presidency following the assassination of Kennedy was influential in the short term for America’s involvement in the Vietnam War due to his determination to end the threat of communism even if the cost was a direct engagement in war, and for the way he handled the trigger of the Gulf of Tonkin Incident. This confrontation consisted of the dubious torpedo attacks on the destroyer USS Maddox stationed off the North Vietnamese coast in the Gulf of Tonkin during a raid on the North Vietnamese defences by the South Vietnamese troops in July 1964. Johnson used this occurrence to inform congress that US ships had come under unprovoked attack (omitting the way the army had taken a more aggressive stance) and to propose America’s preparation for retaliation in an attempt to prove he was bold enough to deal with the communists. This resulted in the ‘Gulf of Tonkin Resolution’ which authorised Johnson to ‘take all necessary steps including the use of armed force’ to defend freedom in South East Asia. This resolution was the justification for America to install active combat troops and respond to the communist threat in conflict although many people thought the war was unconstitutional as there was never a congressional declaration of war. As a consequence of the Gulf of Tonkin incident America’s involvement extended into active conflict and military involvement in the war.
In conclusion the most significant cause of America’s involvement in the Vietnam War was her anti-communist policies in particular the domino theory which made her reject her traditional isolationist views and determine to contain communism. After communism had taken root in China in 1949 the threat seemed to have augmented. The United States and the United Nations had successfully aided the South Koreans in repelling the Communist invasion in the proxy Korean War in 1950 and Vietnam was seen as the next hill to climb in the battle against communism. The war exacted a huge human cost in terms of fatalities including 3 to 4 million Vietnamese from both sides, 1.5 to 2 million Laotians and Cambodians, and 58,159 U.S. soldiers. Despite attempts by the west to demonise the Viet Cong, it is probable that by 1962, over 75% of all south Vietnamese peasants supported the Viet Cong as they were seen as liberators from the unacceptable government of Diem. This in the short term made the risk of South Vietnam turning communism increase, which in the long term heightened America’s involvement and led inevitably to a full scale conflict triggered by the Gulf of Tonkin incident.
