I have written this book in consultation with Vasili Mitrokhin, based on the extensive top secret material (described in Chapter 1) which he has smuggled out from the KGB foreign intelligence archive. For the past quarter of a century, Mitrokhin has passionately wanted this material, which for twelve years he risked his life to assemble, to see the light of day. He wished to reveal "how thin the thread of peace actually was during the Cold War." From that passion this book has been born. I have felt it my duty to ensure that this material, which offers detailed and often unique insights into the workings of the Soviet State and the history of the Soviet Union, achieves the level of public awareness and recognition that it deserves.
Like all archives, those of the KGB require interpretation in the light of previous research and related documents. The end notes and bibliography provide full details of the additional sources used to place Mitrokhin's revelations in historical context. These sources also provide overwhelming corroborative evidence for his genuineness as a source.
Codenames (also known as "worknames" in the case of KGB officers) appear in the text in capitals. Many KGB codenames were used more than once. In such cases, the text and index make clear which individual is referred to. It is also important to note that, although certain individuals were targeted by the KGB, and may have been given codenames, this does not mean that the persons named were conscious or witting agents or sources--or even that they were aware that they were being targeted for recruitment or political influence operations. Similarly, the fact that an individual may have endorsed a position that was favorable to the Soviet Union does not necessarily mean that this person was working as an agent, or agent of influence, for the KGB. The KGB frequently gave prominent policymakers codenames in order to protect the identity of their targets, and to order recruited KGB agents to target such individuals.
For legal reasons, some of the Soviet agents identified in KGB files can be referred to in this book only by their codenames. In a limited number of cases, chiefly because of the risk of prejudicing a possible prosecution, no reference can be made to them at all. These omissions do not, so far as I am aware, significantly affect the main conclusions of any chapter.