It is my understanding that the CCCP started to fall apart when Lithuania declared independence and Ukraine declared it was going to run Ukraine from Kiev.
The breakup was from the bottom up.
The ball got rolling with Solidarity in Poland. Encouraged by the Polish Pope, Reagan and Thatcher, that bit of freedom was like acid that rapidly started eating away the totalitarian state
True - but, only because Gorbachev did not make a Top-Down violent response to stop it.