The moral equivalent of an authorized biography that, against all reason, presents KGB mole H.A.R. (Kim) Philby as an essentially sympathetic character. Philby played a leading role in one of British intelligence's most sensational spy scandals. The son of a noted Arabist, he was recruited by the Soviets during the early 1930's while a student at Cambridge. Despite a leftist background, Philby was able to join the SIS during WW II. A well-connected and competent bureaucrat, he rose quickly through the ranks, eventually becoming chief of counterintelligence. In this and other sensitive posts, Philby did still incalculable harm to Western operations against the USSR and its satellites. Nearly unmasked during a tour of Washington duty in the early years of the Cold War, he was quietly rehabilitated as a resident agent in Beirut. Confronted in 1963 with convincing proof of his duplicity, Philby fled to Russia. Knightley (An Affair of State, The Second Oldest Profession, et al.) was a member of the team of journalists who, in 1967, prepared a series of articles (for London's Sunday Times) on the implications of Philby's defection. Thereafter, he corresponded regularly with the aging turncoat. Last year, just before Philby's death (at 76), the author was granted a number of lengthy interviews with his subject in Moscow. While Knightley does not take the material compiled from these sessions wholly at face value, he relies heavily on it to illuminate the darker corners of Philby's life and career. Like all good cover stories, much if not most of Philby's version of events rings true, and Knightley is scrupulous about putting the old doubledealer's unsupported assertions in appropriately documented context. In the final analysis, though, readers must be willing to take a professional deceiver at his word. An undeniably fascinating, consistently plausible, and ultimately suspect perspective on a man whose trade was treachery.