This publication is an edited volume of Albert and Roberta Wohlstetters' key writings relating to nuclear proliferation and national security affairs, with commentaries by the Wohlstetters' colleagues and students. It also serves as a testament to the continuing relevance of the work of Albert and Roberta Wohlstetter in the fields of nuclear and security policy analysis. Albert and Roberta wrote hundreds of articles and studies on U.S. policy on the Balkans, as well as the Persian Gulf; strategic command and control; intelligence and warning; NATO nuclear planning; U.S.-Russian arms control; strategic and theater missile defenses; the economics and military dangers of civilian nuclear energy; nuclear safeguards and nuclear nonproliferation; and military nuclear strategy and methods of policy analysis and design. Increased concern about the spread of nuclear weapons in the Far and Middle East, the controversy surrounding civilian nuclear cooperation with India, the global revival of nuclear power and debate over its economics and security implications, the controversies surrounding how the Nuclear Nonproliferation Treaty's obligations and rights are being cynically read by Iran and other states - all of these issues have prompted Washington pundits and national security analysts to cite the Wohlstetters' work. The same can also be said of the security concerns recently raised by Islamic fundamentalism, the continued instability of the Balkans, the questions surrounding NATO's future and America's alliances in the Far East, the relevance of nuclear deterrence after the Cold War, and the emergence of ballistic missile defense as a key ingredient in strategic forces and alliance relations. This volume can hardly cover all the insights that the Wohlstetters' work might shed on these topics. Instead, it is designed to make some of the most significant of Albert and Roberta's writings many of which were previously unpublished much more accessible.