The Soviet Union, also known informally as Russia, is a socialist country in Eurasia, founded from 1922 to 1991. Nominally it is a supranational union of national republics, but its governance and economy are highly concentrated in a country that is unified in most respects. Although each republic has its own Communist Party, the union is a one party state with a federal nature, which is ruled by the whole union party and the Communist Party of the Soviet Union. The Russian Republic (itself a federation) has no legal privileges, but in some ways, the Russian nation dominates in culture, politics and language. The capital of the alliance is Moscow.

The Soviet Union originated in the October Revolution in 1917, when the Bolsheviks, led by Vladimir Lenin, overthrew the Russian interim government, which replaced interim Tsar Nicholas II. This established the Russian Socialist Federal Soviet Republic (SFSR), and launched the Russian civil war between the revolutionary "red man" and the counter revolutionary "white man". The Red Army entered several territories of the former Russian Empire and helped the local Communist Party take power through a workers' committee known as the "Soviet Union", which nominally represented workers and farmers. In 1922, the Communists won and united with Russia, the German Caucasus, Ukraine and the Republic of Belarus to form the Soviet Union. After Lenin's death in 1924, collective leadership (Troika) and a brief power struggle, Joseph Stalin came to power in the mid-1920s. Political opposition to his government was suppressed, he dedicated the ideology of the state to Marxism Leninism (created by him) and launched the command economy of the central plan. As a result, the country experienced a period of rapid industrialization and collectivization, laying the foundation for the victory of the Second World War and the rule of Eastern Europe after the war. There was also political paranoia around Stalin, who was expelled from the Communist Party by the arbitrary arrest of many people (military leaders, Communists and civilians), who were then sentenced to death or death. Sent to a correctional facility (gulag system).

Not long before the Second World War, Stalin signed the Treaty of Molotov libentrop and agreed not to invade Nazi Germany. After that, the two countries invaded Poland in September 1939. In June 1941, the German invasion of the Soviet Union opened the largest and bloodiest battlefield in the history of war. In the fierce battle for Stalingrad and the efforts to defeat the axis forces, Soviet war casualties accounted for the largest proportion of the conflict. The Soviet army finally occupied Berlin in 1945. The territory occupied by the Red Army became the state of the Eastern bloc. In 1947, the cold war appeared in 1947 when the Soviet Union Group unified under the Warsaw Treaty and the western countries unified by NATO in 1949 confronted each other.