What role did Ngo Dinh Diem play in the cold war?

Ngo Dinh Diem was South Vietnam's president who was a strong anti-Communist. The Cold War was about tensions between the U.S. and other countries about the containment of communism, and Diem was supported by the United States in hopes that the government in South Vietnam would turn into a stable, reformed one and not resort to communism. This all occurred during the Vietnam war era in the late 1950s.