The collapse of the Soviet Union doesn't have that many conspiracy theories about it, right? There's the Russian assertion that the US promised not to expand NATO around that time, but that's not about the actual collapse of the Soviet Union itself.
Edit: this is a
conspiracy theory I've heard of before from a few Russian authors:
"Events such as the August Coup and Gorbachev’s liberalizing policies were explained in terms of a conspiracy. The theory was that a Western plan to destroy the USSR and plunder its wealth had reached its ultimate goal. Gorbachev would use his liberalizing reforms to rouse liberals in Russia into becoming a pro-Western fifth column to topple both communism and the state (Yablokov 2018). This attempt was resisted by hardliners in the communist government and the KGB (Soldatov and Borgan 2010) which, of course, was positioned as the only force that could stop Western infiltrators."
