He was afraid that Diem's defeat would cause communism to spread to other parts of Asia
He did not want Chi Minh, a communist, to gain control of South Vietnam
After the end of World War II, the United States entered the Cold War. This battle of ideologies between the US and Soviet Union caused a global conflict between the ideas of capitalism and communism. The US, fearing the spread of communism around the world, adapted the policy of containment. This foreign policy was focused on stopping the global spread of communism. In order to do this effectively, the United States entered the Vietnam War in hopes of stopping the spread of communism to Southe Vietnam and stopping communists leaders (like Minh) from gaining more political power.
