Cold War

State of tension between the American-led West and the communist Soviet Union and its satellites from the late 1940s to the late 1980s. A breakdown of cooperation after World War II led to rival power blocs (the North Atlantic Treaty Organization and the Warsaw Pact), international crises (notably the Berlin Blockade and the Cuban missile crisis) and wars by proxy (notably the Korean War and the Vietnam War). A period of detente in the 1970s ended with a Soviet invasion of Afghanistan. In the 1980s, tensions were eased by Mikhail Gorbachev's policies, which finally ended with dissolution of the Soviet Union.