<P> The Soviet Union ( Russian : Сове́тский Сою́з , tr . Sovetsky Soyuz , IPA : ( sɐˈvjɛt͡skjɪj sɐˈjus ) ( listen ) ) , officially the Union of Soviet Socialist Republics ( Russian : Сою́з Сове́тских Социалисти́ческих Респу́блик , tr . Soyuz Sovetskikh Sotsialisticheskikh Respublik , IPA : ( sɐˈjus sɐˈvjɛtskjɪx sətsɨəljɪsˈtjitɕɪskjɪx rjɪˈspubljɪk ) ( listen ) ) , abbreviated as USSR ( Russian : СССР , tr . SSSR ) , was a socialist state in Eurasia that existed from 1922 to 1991 . Nominally a union of multiple national Soviet republics , its government and economy were highly centralized . The country was a one - party state , governed by the Communist Party with Moscow as its capital in its largest republic , the Russian Soviet Federative Socialist Republic . The Russian nation had constitutionally equal status among the many nations of the union but exerted de facto dominance in various respects . Other major urban centres were Leningrad , Kiev , Minsk , Alma - Ata and Novosibirsk . The Soviet Union was one of the five recognized nuclear weapons states and possessed the largest stockpile of weapons of mass destruction . It was a founding permanent member of the United Nations Security Council , as well as a member of the Organization for Security and Co-operation in Europe ( OSCE ) and the leading member of the Council for Mutual Economic Assistance ( CMEA ) and the Warsaw Pact . </P>
when did the soviet union start and end
in Eurasia