The USA increasingly became involved in the conflict in Vietnam after 1949. There are several reasons to explain this involvement and furthermore, these reasons will change between 1949 and Johnson’s deployment of troops in 1965.

The fundamental reason to explain US involvement in Vietnam throughout this time period is the belief that communism was a threat to the capitalist state of America. President Truman was an anti-Communist and he has introduced the Truman Doctrine, a pledge to remove communism from Europe and aiming to stop communism from spreading any further. Kennan outlined Soviet belief and practice and proposed the policy of containment. With the Soviet’s domination of Eastern Europe in the Cold War such as setting up ‘buffer states’ in Poland, Romania etc. , the set up of Cominform and the blockade of Berlin to abandon control of West Germany. It was showing a major threat to the US.

This fear of the threat posed by communism was exacerbated by the events of 1949 when China became a Communist state and the USSR exploded its first own nuclear bomb that the USA was no longer the only nuclear power. These two events prompted the USA to reconsider their policy towards containing communism. US policy now had to be more globally and militarily prepared to stop communism from spreading in Asia countries and even the world. This meant that the growing strength of the Vietminh in North Vietnam could not be ignored as it was believed that if one country fell to communism, then the neighboring countries would also fall such as Laos, Cambodia Thailand or even India, like a row of dominos which was known as the ‘Domino Theory’ with President Eisenhower coming up with this term.

Another reason to explain US intervention in Vietnam is the inability of the South to defend itself against North Vietnam, which was ruled by Ho Chi Minh who was a Communist, and