Soviet Union, Russia, Union of Soviet Socialist Republics, USSR -- (a former communist country in eastern Europe and northern Asia; established in 1922; included Russia and 14 other soviet socialist republics (Ukraine and Byelorussia and others); officially dissolved 31 December 1991)
Russia -- (a former empire in eastern Europe and northern Asia created in the 14th century with Moscow as the capital; powerful in the 17th and 18th centuries under Peter the Great and Catherine the Great when Saint Petersburg was the capital; overthrown by revolution in 1917)
Russia, Russian Federation -- (a federation in northeastern Europe and northern Asia; formerly Soviet Russia; since 1991 an independent state)