The collapse of the Soviet Union was not a revolution. The vast majority of the Soviet people remained passive while state power changed from one set of élites to another. Although society had been activated and politicized by Gorbachev's reforms, it was not through its efforts that the Soviet regime was brought down. As so often in Soviet history, the revolution was from above.
Gorbachev's achievement was to engineer a peaceful abdication of power by the Communist Party. He managed to dismantle the Soviet regime without civil war or major violence, which had been a serious possibility. Why did the Communists not put up more of a fight? Had they lost the will to rule by force? Lost belief in the Soviet system and its ideology? Or reckoned it was time to jump from Lenin's ship? Many former Communists would quickly reappear in politics and business after 1991.
It had not been Gorbachev's intention to end the Revolution when he started out. As a Leninist he had been convinced that it was possible to perfect the Soviet system through reform. Socialism was his goal. In later years he would claim otherwise, that he had aimed to steer a course from Communism to democracy.
But in truth he was a political Columbus, setting out with high ideals to find the promised land, only to discover something else.
Watch this interesting interview with Mikhail Gorbachev on his 80th birthday in 2011. How far do you think his version of events is informed by hindsight? How do you assess his legacy?