There’s Socialism Betrayed: Behind the Collapse of the Soviet Union that despite the sensationalist title is a pretty dry overview of the conditions and policies of the USSR from the 50s on, with most of its focus being on the mid to late 1980s. Its take on Gorbachev seems to essentially be that he was a likable, skilled bureaucrat who was good at enacting other people’s policies but who was very much not cut out for leadership and who relied heavily on others to actually set policy directions for him.

The CIA did not do it. The reactionaries in the USSR did it. Kruschev was the beginning of the end. He and his faction wanted to accumulate wealth, so over the decades following his election they progressively built up the mechanisms for wealth accumulation. This is called liberalization, and it’s where the technical definition of Revisionism comes from - making socialism compatible with liberalism. As this process proceeded, the economy stalled out, the inequality got bad, the repression took on an elective component instead of the necessity post revolution and pre world war. Eventually the contradictions sharpened to crisis and the liberals were firmly in charge of most important levers. They dissolved the union and became the new oligarchs.

I hear the chinese have a few good ones but idk if there are good translations

Gorbachev wrote his own memoirs about it, which is nice as a primary source. But I dont exactly trust his own reasoning lol