In this significant study of U.S. foreign policy, Carlo Maria Santoro traces the origin and implementation of the key principles that guided U.S. actions in the postwar world. The author argues that the period of U.S. neutrality at the beginning of World War II was crucial in developing the concepts of interdependence and national security that remain integral to U.S. foreign policy today. The heart of the book is Santoro's detailed case study of the Council on Foreign Relations' War and Peace Studies project, which was a major source of the theories that have shaped policy-making. Informed by the author's European perspective and sweeping grasp of the literature, the book presents a rich and complex analysis of competing schools of thought and methodological approaches to the making of U.S. foreign policy.