The long history of the Federal Bureau of Investigation under J. Edgar Hoover is studded with serious questions about the BureauOs professionalism and accountability. Revelations in the recent cases of Wen Ho Lee, Robert Hannsen, and Timothy McVeigh illustrate these misgivings. In Chasing Spies, Athan Theoharis, historian and perhaps the foremost authority on the FBIOs record, raises urgent new uncertainties about the BureauOs behavior_and about the prospects for giving the FBI expanded powers of surveillance during the current national emergency. Mr. Theoharis here redefines the politics of the World War II and cold war eras, moving the debate beyond the narrow perspective triggered by the release of KGB records and intercepted Soviet consular reports (the Venona messages). The intriguing issue, he argues, is not the effectiveness of Soviet espionage activities as supported by the new evidence. Nor is it the long-standing charges of Osoftness toward communismO in the Roosevelt and Truman administrations. The real issue, he says, is the failure of the FBI to apprehend and convict Soviet agents. Based on meticulous research in FBI files, Chasing Spies uncovers the FBIOs role in the most important espionage cases of the cold war years. The book shows how secrecy immunized FBI operations from critical scrutiny and enabled FBI officials to mask their counterintelligence failures while promoting a politics of McCarthyism.