An unusual biography cum investigation of an academic caught up in a Cold War controversy. Kirschner (History/Simon Fraser Univ., British Columbia; The Paradox of Professionalism, not reviewed) initially aimed to help his older colleague Halperin (19061995) write his memoirs. But this story of a McCarthy-era political refugee grew, and the author not only incorporates Halperin's memories but applies his own skeptical sleuthing. Though lucidly written, the book's biographical depth may slow readers mainly curious about whether Halperin did spy for Soviets during WW II. Kirschner sketches Halperin's youth in Boston, the son of Yiddish-speaking immigrants, his undergraduate years at Harvard, and teaching stint at the University of Oklahoma, where he became a scholar of Latin America and an ``issue-oriented'' fellow traveler. Halperin was recruited in 1941 as a researcher on Latin America for the federal agency that preceded the OSS and CIA. He went to Boston University in 1949, but in 1953 the Senate Internal Security Subcommittee subpoenaed him, citing testimony by a Soviet courier that he had spied for the Soviets during the war. Halperin took the Fifth Amendment but also denied committing espionage. The author offers intriguing accounts of Halperin's self-imposed exile: five years in Mexico within the community of American expatriate radicals; a three-year stint in the Soviet Union, which soured him on the promise of Communism; a subsequent move to Cuba, where he also concluded that socialism had failed; and his final relocation to Canada--ironically, to a campus seething with socialist slogans. In a final chapter, Kirschner conducts a near-exhaustive lineup of evidence on both sides; he concludes that Halperin was more of an ideologue than he let on and that it ``seems improbable'' that his accuser perjured herself. A minor tale of the Cold War, but well told.