Why do states make disingenuous treaty commitments? Under what conditions will countries refrain from entering cooperative agreements with which they do not expect to comply? This article addresses these questions by analyzing how states that are pursuing nuclear weapons treat the nuclear Nonproliferation Treaty (NPT). The authors develop a distinction between two types of noncooperative behavior. The first is cheating while part of the NPT (predation) and the second is pursuing nuclear weapons outside of the treaty (abstention). The authors argument is that democratic proliferators are more likely to abstain because executives in democracies are domestically constrained to a greater degree than authoritarian leaders. Statistical tests in a sample of all countries with active nuclear weapons programs from 1968 to 2004 provide evidence in favor of our argument. Controlling for confounding variables and the factors that motivate states to pursue nuclear weapons, the results show that states with greater constraints on executive authority are less likely to choose predation. Yet, electoral mandates do not appear to dissuade governments from making disingenuous treaty commitments. These findings have important implications for nuclear proliferation, the credibility of international commitments, and efforts to link domestic political institutions with international outcomes.