One of his five best books on Soviet espionage, as told to the Wall Street Journal:
Spies: The Rise and Fall of the KGB in AmericaRead about the other books on the list.
by John Earl Haynes, Harvey Klehr and Alexander Vassiliev (2009)
This huge tome is the best catalog yet of Americans who spied for the Soviet Union and the information that they may have passed on. For decades, ideological combatants have argued bitterly over the complicity of players like Alger Hiss, Harry Dexter White and J. Robert Oppenheimer. "Spies" sheds much helpful light, thanks to the collaboration of John Earl Haynes and Harvey Klehr—Cold War espionage scholars of the first rank—with Alexander Vassiliev, a former KGB agent who walked out of his agency's secret archives with thousands of pages of notes and transcriptions. Curious readers can now discover exactly who Julius Rosenberg recruited, who turned the Soviets down (Oppenheimer) and who, to the surprise of many, worked as a courier passing information: the American writer I.F. Stone, whose KGB code name was "Pancakje."
Also see Jonathan Miles's five best books about the secrets of espionage.