The Cold War began in the 1940s, primarily following the end of World War II in 1945. The ideological conflict between the United States and the Soviet Union emerged, marked by political tension, military rivalry, and economic competition. This period witnessed the spread of communism and counter-efforts by the U.S. to contain it, leading to events like the Berlin Blockade and the Korean War. The Cold War influenced global politics, shaping alliances and conflicts for decades.