USSR was disintegrated in the period ______?

The dissolution of the Soviet Union [e] (1988–1991) was the process of internal political, economic, and ethno-separatist disintegration within the USSR , which resulted in the end of its existence as a sovereign state. Being its ultimate unintended aftermath, it brought an end to General Secretary (later also President ) Mikhail Gorbachev 's effort to reform the Soviet political and economic system in an attempt to stop a period of political stalemate and economic backslide , known as the "Era of Stagnation" or simply as " Zastoy " ( Russian for "stagnation" or "stasis"). In late 1991, amidst the catastrophic political crisis and several republics already breaking off the Union, the leaders of three of its founding members (the fourth one being dissolved in the 1930s) declared that the Soviet Union no longer existed , eight more republics joined their declaration shortly thereafter. Gorbachev had to resign and what was left of the parliament to formally acknowledge the collapse as a fait accompli .