The Cold War was a period of geopolitical tension between the United States and the Soviet Union. It lasted from the late 1940s to the early 1990s. The conflict was characterized by political, economic, and ideological rivalry rather than direct military confrontation. The Soviet Union played a central role as the leading communist power, engaging in a global ideological struggle with the capitalist West, particularly the United States, through proxy wars, arms race, espionage, and propaganda.