A common theme in a number of books I've read recently is that, post-1990, Western historians benefitted greatly from opening of the KGB, Foreign Affairs, and other archives previously off-limits to them. Nonetheless, the exact nature of the change in perspective is fairly vague, so I was wondering whether anyone had some concrete examples of how the access to previously unseen primary evidence challenged traditional views?
Or, alternatively, is my interpretation of the archives opening completely false?
The Mitrokhin Archive was one of the biggest goldmines of Soviet secret intelligence, but this wasn't obtained by any kind of olive-branch diplomacy. It came because Mitrokhin, the guy who stole it all, had gradually become a Western sympathizer by listening to illegal radio broadcasts and having become disillusioned with the Soviet system before sneaking historical data out of the KGB library after the end of his shift each day and burying it under his dacha. Then when he migrated to the UK in 1993(?) he got British help in extracting the documents.
It contained a lot of history on KGB operations from the end of World War I, when it was called the Cheka/NKVD, all the way up to shortly before the end of the Cold War. A lot of it helped the West understand how successful and unsuccessful Soviet spies were, including finding out some spies that had previously been unknown, and showing how deeply the Soviets had penetrated Science/Tech departments, universities and foreign governments (Alger Hiss, Guy Burgess, etc).
As a follow-up question, how many archives actually were opened? In his Decline and Fall of the Soviet Empire, journalist Fred Coleman describes how the KGB archives were inherited, intact and closed, by the Russian Federation security service. They tried unsuccessfully to make a deal with Newsweek to publish a few selected records; when the deal fell through, virtually everything remained closed. Was this typical? Or were even the KGB archives later opened?