Proxy wars between the United States and the Soviet Union were frequent during the Cold War. Both sides eagerly tried to expand their influence and ideology around the globe. They supported opposing sides with arms, training, and assistance in numerous proxy wars throughout the Cold War. Washington and Moscow were bitter foes, but a direct military confrontation between the two would have led to World War III. Neither side wanted another world war, especially because both possessed nuclear weapons.

Proxy wars started immediately after World War II. Countries that had been invaded and occupied by Axis forces had no central government. Communists in China and Greece were backed by Moscow, and their opponents were supported by Washington. Communists won in China, but they lost in Greece. The "loss" of China in 1949 was a huge blow to American foreign policy, and Washington was determined to prevent Communism from expanding further.

The Korean War (1950–1953) was a major proxy war. Moscow supported Communist North Korean and Chinese forces during that conflict. Peace was achieved only after Joseph Stalin died. This war ended in stalemate.

Both the United States and the Soviet Union suffered humiliating losses in proxy wars. America's participation in the Vietnam War (1957–1975) was an unmitigated disaster for both Americans and Vietnamese. North Vietnam had been supported by both Moscow and Beijing. The Soviet Union suffered its worst defeat when it tried to conquer Afghanistan in the 1980s. Washington had helped the Taliban and other Muslim factions that fought the Soviets.

Although the Cold War is over, there are still proxy wars in the world today.