After 1945 two superpowers faced each other without direct full-scale war. The Cold War was the prolonged geopolitical, ideological, and military rivalry between the United States and its allies and the Soviet Union and its bloc. It lasted roughly from the late 1940s until the Soviet collapse in 1991.

Competition unfolded through arms races, proxy wars, espionage, propaganda, and space exploration. Europe was divided by the Iron Curtain; crises over Berlin, Cuba, and elsewhere brought the world close to nuclear conflict. Decolonizing regions became arenas for influence.

Archival releases from both sides have refined understanding of decision-making and misperception. The period left nuclear arsenals, military alliances, and political cultures shaped by permanent emergency. Its end reconfigured global politics but did not erase every local conflict it had once framed.

• Post-1945 rivalry between U.S. and Soviet blocs
• Marked by arms race and proxy conflicts
• Ended with Soviet dissolution in 1991
• Shaped global alignments for decades