This dissertation examines the origins and evolution of neoconservatism as a philosophical and political movement in America from 1945 to 1980. I maintain that as the exigencies and anxieties of the Cold War fostered new intellectual and professional connections between academia, government and business, three disparate intellectual currents were brought into contact: the German philosophical tradition of anti-modernism, the strategic-analytical tradition associated with the RAND Corporation, and the early Cold War anti-Communist tradition identified with figures such as Reinhold Niebuhr. Driven by similar aims and concerns, these three intellectual currents eventually coalesced into neoconservatism. As a political movement, neoconservatism sought, from the 1950s on, to re-orient American policy away from containment and coexistence and toward confrontation and rollback through activism in academia, bureaucratic and electoral politics. Although the neoconservatives were only partially successful in promoting their transformative project, their accomplishments are historically significant. More specifically, they managed to interject their views and ideas into American political and strategic thought, discredit détente and arms control, and shift U.S. foreign policy toward a more confrontational stance vis-à-vis the Soviet Union. Simultaneously, the neoconservatives institutionalized nuclear wariii fighting (the idea that it is possible to fight and win a nuclear war) in U.S. strategic doctrine. In re-orienting U.S. policy in the 1970s, the neoconservatives also laid the foundations for the policies of the first Reagan Administration. This dissertation challenges the prevailing conceptions about neoconservatism in three ways. First, it demonstrates that neoconservatism was not primarily a sociological and literary phenomenon centered on the work of the so-called “New York intellectuals.” Second, it demonstrates that the philosophical foundation of neoconservatism was not socialism, but German philosophy. Third, that neoconservatism’s primary policy focus was not Israeli interests and security, but the political and strategic competition between the United States and the Soviet Union.