The history of the Soviet Union began with the ideals of the Bolshevik Revolution and ended in dissolution amid economic collapse and political disintegration. Established in 1922 following the Russian Civil War, the Soviet Union became a one-party state under the Communist Party. Its early years under Lenin were marked by socialist policies and the New Economic Policy (NEP), which allowed some market-oriented reforms.
The rise of Joseph Stalin in the late 1920s ushered in an era of intense centralization and totalitarianism. Stalin's rule was characterized by forced collectivization of agriculture, rapid industrialization, and the Great Purge.
The Soviet Union, one of the Big Four Allied powers alongside the United States, the United Kingdom, and China, played a crucial role in the Allied victory in World War II. The conflict came at a tremendous human cost, with millions of Soviet citizens dying during the war.
The Soviet Union emerged as one of the world's two superpowers, leading the Eastern Bloc in opposition to the Western Bloc during the Cold War. This period saw the USSR participate in an arms race, the Space Race, and conflicts around the globe. Nikita Khrushchev later initiated a de-Stalinization process, leading to a period of relative liberalization known as the Khrushchev Thaw.
The subsequent era under Leonid Brezhnev, sometimes referred to as the Era of Stagnation, was marked by economic difficulties, political corruption, and rigid political leadership. Military expenditures and the costs of maintaining the Eastern Bloc placed additional pressure on the Soviet economy.
In the 1980s, Mikhail Gorbachev introduced glasnost (openness) and perestroika (restructuring) in an attempt to revitalize the Soviet system. Instead, these reforms accelerated its unraveling. Nationalist movements gained momentum across the Soviet republics and Communist Party control weakened. The Soviet Union formally dissolved on 26 December 1991, ending nearly seven decades of Soviet rule.