During the Cold War between the United States and the Soviet Union, the United States' major policy was to limit the spread of Soviet-influenced communism. Beginning in the years after World War II, the idea led to numerous covert military actions as well as major wars in Vietnam and Korea. The idea, known as "containment," was first articulated by George Kennan.

Containment

George F. Kennan, a foreign service officer, first mentioned the idea of containment in a 1947 article in the magazine ''Foreign Affairs.'' Kennan wrote about Russian "expansive tendencies," and how the long-term approach of the United States should be to contain these tendencies. More specifically, this referred to the need to limit or stop the spread of communism around the world.