This dissertation addresses the role of the U.S. Army as an instrument of national and alliance strategy in the era of the Cold War. The army was confronted with the fundamental question of its utility in the nuclear age. This dissertation argues that after the Korean War army leaders pursued a consistent policy to create a force that could deter limited, i.e., conventional and tactical-nuclear war in Central Europe. This policy resulted in a three-decade long transition process, as the army had to respond to influences ranging from the Soviet threat to inter-service rivalry, budgetary concerns, rapidly evolving technology, and military and political developments in Europe and Asia. The transition process occurred in three stages. First, army leaders redefined the mission of their institution from war-fighting to the deterrence of war. Then, the structure of combat divisions was altered to reflect the requirements of nuclear as well as conventional battlefields. Finally, and only after the Vietnam War, doctrine was introduced that combined specific objectives in Central Europe, modern divisional structure, weapons technology, and newly defined principles of operational art in a coherent system of air and land warfare. At the heart of the dissertation rests the question of strategic decision-making and the impact of military institutions. But it also addresses NATO's military and political capabilities and considers the effect of nuclear weapons on land warfare and the deterrence of war. Moreover, it is a study of civil-military relations in the United States. Finally, it offers a fresh view of the Vietnam War by placing both the periphery and center of the Cold War in the context of potentially devastating nuclear war. Scholarship of the Cold War to date has emphasized the effects of nuclear deterrence and neglected the contribution of ground forces to the prevention of war. This dissertation is based on archival research in Europe and the United States, including the archives of NATO and the German military, the U.S. National Archives, the National Security Archive, several presidential libraries, and other major repositories of manuscripts of diplomats, military officers, and political leaders.