World War II casualties of the Soviet Union in the context of "Soviet"

The Union of Soviet Socialist Republics (USSR), commonly known as the Soviet Union, was a transcontinental country that spanned much of Eurasia from 1922 until it dissolved in 1991. During its existence, it was the largest country by area, extending across eleven time zones and sharing borders with twelve countries, and the third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of national republics, the largest and most populous of which was the Russian SFSR. In practice, its government and economy were highly centralized. As a one-party state governed by the Communist Party of the Soviet Union (CPSU), it was the flagship communist state. Its capital and largest city was Moscow.

The Soviet Union's roots lay in the October Revolution of 1917. The new government, led by Vladimir Lenin, established the Russian SFSR, the world's first constitutionally communist state. The revolution was not accepted by all within the Russian Republic, resulting in the Russian Civil War. The Russian SFSR and its subordinate republics were merged into the Soviet Union in 1922. Following Lenin's death in 1924, Joseph Stalin came to power, inaugurating rapid industrialization and forced collectivization that led to significant economic growth but contributed to a famine between 1930 and 1933 that killed millions. The Soviet forced labour camp system of the Gulag was expanded. During the late 1930s, Stalin's government conducted the Great Purge to remove opponents, resulting in large scale deportations, arrests, and show trials accompanied by public fear. Having failed to build an anti-Nazi coalition in Europe, the Soviet Union signed a non-aggression pact with Nazi Germany in 1939. Despite this, in 1941 Germany invaded the Soviet Union in the largest land invasion in history, opening the Eastern Front of World War II. The Soviets played a decisive role in defeating the Axis powers while liberating much of Central and Eastern Europe. However they would suffer an estimated 27 million casualties, which accounted for most losses among the victorious Allies. In the aftermath of the war, the Soviet Union consolidated the territory occupied by the Red Army, forming satellite states, and undertook rapid economic development which cemented its status as a superpower.

The history of the Soviet Union between 1927 and 1953, commonly referred to as the Stalin Era or the Stalinist Era, covers the period in Soviet history from the establishment of Stalinism through victory in the Second World War and down to the death of Joseph Stalin in 1953. Stalin sought to destroy his enemies while transforming Soviet society with central planning, in particular through the forced collectivization of agriculture and rapid development of heavy industry. Stalin consolidated his power within the party and the state and fostered an extensive cult of personality. Soviet secret-police and the mass-mobilization of the Communist Party served as Stalin's major tools in molding Soviet society. Stalin's methods in achieving his goals, which included party purges, ethnic cleansings, political repression of the general population, and forced collectivization, led to millions of deaths: in Gulag labor camps and during famine.

World War II, known as "the Great Patriotic War" by Soviet historians, devastated much of the USSR, with about one out of every three World War II deaths representing a citizen of the Soviet Union. In the course of World War II, the Soviet Union's armies occupied Eastern Europe, where they established or supported Communist puppet governments. By 1949, the Cold War had started between the Western Bloc and the Eastern (Soviet) Bloc, with the Warsaw Pact (created 1955) pitched against NATO (created 1949) in Europe. After 1945, Stalin did not directly engage in any wars, continuing his totalitarian rule until his death in 1953.