What Does It Take to Deter? Regional Power Nuclear Postures and International Conflict

Existing nuclear deterrence scholarship evinces a pervasive ‘‘existential bias,’’ assuming that once a state merely possesses nuclear weapons, it should be able to deter armed conflict. The empirical literature expresses this bias by simply dichotomously coding a state based on whether it has nuclear weapons, thereby treating all nuclear states as equivalent. Thus, whether nuclear weapons deter conflict, and how much is required to do so, is unclear. This article shifts the unit of analysis away from nuclear weapons to postures, hypothesizing that different nuclear postures are distinct and generate differential deterrent power, particularly amongst the nonsuperpower states which comprise the lion’s share of nuclear powers. I find that an asymmetric escalation nuclear posture uniquely deters conflict initiation and escalation. Not only do small arsenals have little deterrence success, but I find that even assured retaliation postures fail to deter intense conventional conflict. This suggests that the deterrence dividend is distributed unequally across nuclear powers, and that states may need to do more than simply acquire nuclear weapons to successfully deter conventional attacks.