The USSR officially dissolved on December 26, 1991. This marked the end of the Soviet Union, leading to the independence of its republics and significant geopolitical changes in Eastern Europe and Central Asia. The dissolution was formalized by the Belavezha Accords, which were signed by leaders of Russia, Ukraine, and Belarus earlier that month.
If this question concerns why the USSR collapsed in '91, its because the Soviets went (or were going) bankrupt.
The USSR took over Czechoslovakia on August 20, 1968.
1980.
In June 1941.
Stalin was extremely effective at modernizing and industrializing the USSR. He had several 5 year plans for improving the USSR and he carried them out. He took Russia from the 19th century into the 20th century.
The U.S.S.R was dis-banded in 1991.
To industrialize and modernize the USSR.
Five-Year-Plan
1985, according to Encyclopedia Britannica.
The USSR Luna 10, 1966
November 3, 1957
European nations in the western part of Europe and in the eastern part of Europe, for the most part were glad to see the menace of the USSR dissolve. The previously communist nations were glad to be free of the USSR and in the western nations they were happy that their eastern neighbors would be free and create governments that respected the civil rights that were denied to them by the USSR.