The missile defence policy of the US plays a crucial role in international affairs and is normally studied from a US perspective. This book is different, it delivers a sharp analysis of regional and national variations and integrates them with US viewpoints to present a rounded and comprehensive study. What will be the international ramifications of American plans to deploy a comprehensive national missile defence policy? This is a key question for all those wishing to build a sense of the global future and is here answered with clarity and rigour by expert contributors. This new study breaks the mould of traditional assessments that focus exclusively on the US world picture and are inevitably one-dimensional. Here we see that US action automatically entails reactions as this text advances a more balanced approach. By integrating a focus on US policy with a strong analysis of regional dynamics, it demonstrates that the global ramifications of US policy are indeed contingent upon distinct regional and national variations. These differences in turn have consequences both for the challenges the US faces in relation to missile defence and for the future of world politics. This is an innovative and groundbreaking study that contains lessons for those wishing to safeguard the future by becoming alert to its challenges and complexities.