Symposium: The Constraining Effect of Arms Control Treaties

[This is a post-publication review symposium] Matthew Fuhrmann and Yonatan Lupu’s “Do Arms Control Treaties Work?” offers an optimistic take on the Nuclear Nonproliferation Treaty (NPT), as they present evidence consistent with the claim that ratifying the NPT reduces the chances that signatories pursue nuclear weapons. In this symposium, two other experts on nuclear politics weigh in on the study. Rupal Mehta, after indicating that the results can be consistent with several different causal stories, notes that the NPT’s very effectiveness, especially in clarifying what actions will and won’t provoke preventive action, may incentivize more states to pursue latent nuclear capability than otherwise might, with unclear consequences for future peace and stability. Alexandre Debs looks at the theoretical underpinnings of the empirical model, (a) questioning the required assumption of similarities between the NPT and other global treaties and (b) emphasizing the limits of selection on observables in achieving causal identification. In their response, the authors offer a defense of their matching strategy and, prompted by Mehta’s and Debs’s comments, discuss future lines of inquiry.