Humanities › History & Culture The History of Containment Policy George Kennan and American Foreign Policy During the Cold War Share Flipboard Email Print Bettmann / Getty Images History & Culture Military History Battles & Wars Key Figures Arms & Weapons Naval Battles & Warships Aerial Battles & Aircraft Civil War French Revolution Vietnam War World War I World War II American History African American History African History Ancient History and Culture Asian History European History Genealogy Inventions Latin American History Medieval & Renaissance History The 20th Century Women's History View More By Kennedy Hickman Military and Naval History Expert M.A., History, University of Delaware M.S., Information and Library Science, Drexel University B.A., History and Political Science, Pennsylvania State University Kennedy Hickman is a historian, museum director, and curator who specializes in military and naval history. He has appeared on The History Channel as a featured expert. our editorial process Facebook Facebook Kennedy Hickman Updated August 09, 2019 Containment was a foreign policy strategy followed by the United States during the Cold War. First laid out by George F. Kennan in 1947, the policy stated that communism needed to be contained and isolated, or else it would spread to neighboring countries. American foreign policy advisors believed that once one country fell to communism, each surrounding country would fall as well, like a row of dominoes. This view was known as the domino theory. Adherence to the policy of containment and domino theory ultimately led to U.S. intervention in Vietnam as well as in Central America and Grenada. Containment Policy The Cold War began after World War Two when nations formerly under Nazi rule ended up split between the conquests of the U.S.S.R. and the newly freed states of France, Poland, and the rest of Nazi-occupied Europe. Since the United States had been a key ally in liberating western Europe, it found itself deeply involved in this newly divided continent: Eastern Europe wasn't being turned back into free states, but rather being placed under the military and political control of the Soviet Union. Further, western European countries appeared to be wobbling in their democracies because of socialist agitation and collapsing economies, and the United States began to suspect that the Soviet Union was deliberately destabilizing these countries in an effort to bring them into the folds of communism. Even countries themselves were dividing in half over the ideas of how to move forward and recover from the last world war. This resulted in a lot of political and military turmoil for the years to come, with such extremes as the establishment of the Berlin Wall to separate East and West Germany due to the opposition to communism. The United States developed its policy of containment to prevent communism from spreading further into Europe and the rest of the world. The concept was first outlined in George Kennan's "Long Telegram," which he sent from the U.S. Embassy in Moscow. The message arrived in Washington, D.C., on February 22, 1946, and was circulated widely around the White House. Later, Kennan published the document as an article titled "The Sources of Soviet Conduct" — which became known as X Article because Kennan used the pseudonym "Mr. X." The policy of containment was adopted by President Harry Truman as part of his Truman Doctrine in 1947, which redefined America's foreign policy as one that supports the "free people who are resisting attempted subjugation by armed minorities or outside pressures." This came at the height of the Greek Civil War of 1946-1949 when much of the world was waiting to see which direction Greece and Turkey would go, and the United States agreed to help both countries to avoid the possibility that the Soviet Union would lead them to communism. The Creation of NATO Acting deliberately (and at times aggressively) to involve itself in the border states of the world and prevent them from turning communist, the United States spearheaded a movement that would eventually lead to the creation of the North Atlantic Treaty Organization (NATO). The group alliance represented a multi-national commitment to halting the spread of communism. In response, the Soviet Union signed an agreement called the Warsaw Pact with Poland, Hungary, Romania, East Germany, and several other nations. Containment in the Cold War: Vietnam and Korea Containment remained central to American foreign policy throughout the Cold War, which saw rising tensions between the United States and the Soviet Union. In 1955, the United States entered what some historians consider a proxy war with the Soviet Union, by sending troops into Vietnam to support the South Vietnamese in their battle against the communist North Vietnamese. The United States' involvement in the war lasted until 1975, the year the North Vietnamese captured the city of Saigon. A similar conflict took place during the early 1950s in Korea, which was likewise divided into two states. In the fight between North Korea and South Korea, the United States backed the South, while the Soviet Union backed the North. The war ended with an armistice in 1953 and the establishment of the Korean Demilitarized Zone, a 160-mile barrier between the two states.