A systematic critical survey of American strategic thinking and the strategic culture in which it is formed. In particular, this book seeks to interrogate the theory and strategy of nuclear deterrence, and its relationship to the concept of missile defence. Drawing widely on the theoretical literature in international relations and strategic studies, it identifies the key groups that have competed over America's nuclear policy post-1945 and examines how the concept of missile defence went through a process of gestation and intellectual contestation, leading to its eventual legitimization in the late 1990s. Steff sheds light on the individuals, groups, institutions and processes that led to the decision by the Bush administration to deploy a national missile defence shield. Additionally, Steff systematically examines the impact deployment had on the calculations of Russia and China. In the process he explains that their reactions under the Bush administration have continued into the Obama era, revealing that a new great power security dilemma has broken out. This, Steff shows, has led to a decline in great power relations as a consequence.