The Soviet Union or Union of Soviet Socialist Republics (USSR) was a nation that existed between 1922 and 1991. The Soviet Union emerged as a direct result of the Russian Revolution, which took place in 1917 and transformed Russia into a socialist nation. The transformations in this led to its unification with other Soviet republics in the early 1920s.
The Soviet Union was the world symbol of socialism and led the communist bloc during the Cold War years. At the end of the 1970s, the Soviet Union began a strong economic crisis that led the country into a recession and a political crisis, which contributed to the fragmentation of the Soviet Union and its end in 1991.