How do domestic political institutions affect international conflict? Democratic peace theorists argue that jointly-democratic dyads are less likely to engage in war than other types of states, but these explanations cannot account for the large number of militarized conflicts that fall short of...

Why do nuclear weapons spread? Using new data on sensitive nuclear transfers, this article analyzes the determinants of nuclear proliferation. The author first describes a simple logic of the technical and strategic advantages that potential nuclear proliferators can gain by importing nuclear...