The Causes of Nuclear Weapons Proliferation

This critical review of the new political science literature on the causes of nuclear weapons proliferation consists of seven parts. The first section briefly presents what we know about which states developed nuclear weapons and which states started but abandoned weapons development programs. I highlight the problems that result from uncertainty about the accuracy and completeness of the data. The second and third sections review the literature on the spread of the technical capability to develop nuclear weapons. We still lack robust knowledge about the relationship between the development of civilian nuclear power programs and nuclear weapons acquisition. The next two sections review the literature on the demand for nuclear weapons. Comparative case studies and statistical studies have improved our understanding of the diversity of motives for weapons development and restraints, but serious gaps in our knowledge remain. The sixth section outlines alternative theories about the potential impact of the nuclear Non-Proliferation Treaty (NPT) on nuclear weapons programs decisions. Finally, I lay out a future research agenda to address the weaknesses in our current understanding of the causes of nuclear proliferation.