Bas, Muhammet A.Coe, Andrew J.Gheorghe, Eliza2025-02-212025-02-212024-010022-3816https://hdl.handle.net/11693/116592When international laws or norms are violated, an enforcer can punish the violator, offer concessions for its renewed compliance, or tolerate it. Punishment is often costlier than concessions or toleration but signals to other states that violation will be met with penalties rather than rewards or acceptance. By influencing other states’ expectations about what will happen if they get caught violating, the choice of response can thus encourage or discourage subsequent compliance. Anticipating this, an enforcer is more willing to punish when it faces a larger audience of potential near-term violators. Focusing on the nuclear nonproliferation norm, we show statistically that enforcer responses appear to have affected whether states subsequently pursued the bomb historically and that this effect is stronger than other hypothesized determinants of proliferation decisions. We also use primary sources to document that policy makers recognized and heeded this influence in a range of cases.EnglishInternational lawNormsEnforcementNonproliferationArticle10.1086/7269471468-2508