Abstract: How do nuclear agreements keep parties from proliferating? One perspective is that such deals constrain these states’ nuclear capacity, reducing their ability to produce weapons at an efficient cost. Current approaches cannot test this due to inappropriate measures of capacity and lack of appropriate comparison group. We address both of these points, gathering new data to estimate proficiency and adopting the generalized synthetic control method. We then evaluate the constraining effects of deals the United States implemented with Japan, South Korea, and Taiwan as well as the Declaration of Iguacu between Brazil and Argentina. Our results indicate that the constraining effect is minimal.
