the Soviet Union collapsed in December 26, 1991
the collapsed of the soviet union:milestone-1989-1992
hope it helps thx
Dissolution of the Soviet Union/Date 26 December 1991
Explanation: The dissolution of the Soviet Union occurred on 26 December 1991, officially granting self-governing independence to the Republics of the Union of Soviet Socialist Republics. It was a result of the declaration number 142-Н of the Supreme Soviet of the Soviet Union.