This enormous and ambitious work is a reaction against several recent fashionable orthodoxies: an optimistic reading of history that predicts a peaceful transition to global capitalism, a conservative reading of the French Revolution that sees it as a forerunner of Bolshevik terror, and a tendency to stress the similarities between communist and fascist versions of totalitarianism. Comparing the French and Russian revolutions, Mayer focuses on how they reflected the struggle between revolutionary ardor and counterrevolutionary resistance, antireligious fervor and religious intransigence. He stresses the contingencies affecting revolutionary terror rather than the ideology or psychology of leaders. And his examination of conceptual signposts such as revolution, violence, vengeance, and terror is a useful contribution to the history of ideas. But he traces mostly the revolutions' main developments -- the initial period of terror, the peasant wars, the battles against established religion, the "externalization" of the French Revolution by Napoleon, and the "internalization" of the Russian one by Stalin. The last is presented as a result of the West's quarantine on the Soviet Union -- first through containment, then through international exclusion. Mayer does not deny that Soviet terror reached monstrous proportions, but he does distinguish it sharply from Hitler's genocidal policies. Stalin, he writes, was reacting against the Soviet regime's perilous situation in the world. Mayer then concludes by rehashing the revisionist view of the Cold War, interpreting Soviet policy as essentially defensive and driven by security concerns, not ideology. And again, he blames the West for feeding Stalin's siege mentality. This thesis, alas, needs more documentation to persuade. Nonetheless, the book's strength lies in its sharp analysis of interacting forces and events, not in its generalizations.