5 - Enforcement

Summary

The nuclear nonproliferation regime lacks formal enforcement mechanisms, but this does not mean that violations of nonproliferation commitments always go unpunished. States that violate the NPT routinely face pressure from others to change their behavior, including through economic sanctions. But the lack of formal enforcement measures does contribute to significant variation in the states that are targeted for punishment – enforcement is always at the discretion of the punishing state. Why do some states face punishment while the transgressions of others are overlooked? This chapter argues that enforcing states look to the policy preferences of violators for signals about the likelihood that enforcement will change state behavior and about the cost to the international community of allowing the violation to continue. Patterns of institutional membership within the larger regime help to credibly reveal the preferences of state parties. Using data on membership in the various agreements that make up the nuclear nonproliferation regime, this chapter shows that violating states are less likely to face costly enforcement action the more embedded they are within the regime.