The cold war, which began as the second world war ended, created a new set of international constraints and opportunities that shaped the region. After 1949, the cold war was in full swing, which added very significant layers of external influence. The Soviet Union and the United States divided the world into East and West spheres of influence. In several regions, they competed for power and even fought proxy wars. Southeast Asia became one of the Cold War’s key terrains. The Vietnam war (1955-75) represented the most important application of the united states’ containment policy, by which the US sought to prevent the spread of communism. America governments were motivated by the belief that losing in Vietnam might lead to a “domino effect” across southeast asia. In this respect, they were somewhat vindicated as the loss of the war in 1975 triggered not only a communize victory in Vietnam but also the downfall of authoritarian rule and replacement by communist regimes in neighbouring Cambodia and Laos. The US government was determined to prevent other communize movements from gaining power. It played a role in supporting the Indonesia military’s suppression of communists in Indonesia in 1965, after a failed coup attempt allegedly launched by the communist party. It provided further military aid and political support to Suharto’s anti-communist, authoritarian regime that began in 1965. In the Philippines, the united states provided military aid, training and strong political support to contain the influence of the new people’s army, the armed wing of the Philippine communist party. It gave its unwavering support for the Marcos dictatorship (1972-86), which was strongly anti-communist. It would not be an exaggeration to argue that the fate of many emerging independent states was closely tied to the competition of the United States and the Soviet Union as well as China in the battle between communist and non-communist states.