The Mitrokhin archive II - Christopher M Andrew|Vasili Mitrokhin

In 1992, MI6 exfiltrated Vasili Mitrokhin, the most senior activist in the KGB, who had been responsible for running the KGB archives. He had noted thousands of documents, described by the FBI as 'the greatest single cache of intelligence ever received by the West.'
This archive resulted in many prosecutions, some of which are still ongoing.

After his defection, Mitrokhin teamed up with Christopher Andrew, Professor of Modern History at Cambridge and the world's leading intelligence scholar.
Their first volume, The KGB in Europe and the West, revealed the extent of KGB penetration of what they called The Main Adversary and the existence of a previously unknown nuclear spy, Melita Norwood.
The second volume, The KGB and the World, continues the revelations from the sublime to the absurd - which Third World leaders were in the pay of the KGB, precisely how extensive KGB penetration of foreign governments was, and how KGB agents were instructed to assess the spread of the influence of rival Chinese communism (by going round African capitals trying to count the changing number of posters of Mao Tse-tung in shops and public buildings...)