Soviet Union began a slow process of democratization that eventually destabilized Communist control and contributed to the collapse of the Soviet Union.
A number of events and uprisings in the 1980 are led to the collapse of the Soviet Union. ... Last, in the Soviet Union, the failed August Coup in 1991 led to the end of the Communist party in USSR. All of these events led to the end of communism and the making of a democratic Russia.
it collapsed on December 26, 1991