Nuclear weapons' effects on an actor's success in coercive diplomacy are in part a function of how nuclear weapons change the perceived costs of conflict. The authors argue that states can improve their allotment of a good or convince an opponent to back down and have shorter crises if their opponents have greater expected costs of crisis. Noting that nuclear weapons increase the costs of full-escalation scenarios but decrease their probability, it is uncertain what impact nuclear weapons should have on expected costs of conflict. The authors assess crisis outcomes from 1945 to 2000 using the International Crisis Behavior data set. The evidence confirms that nuclear actors are more likely to prevail when facing a nonnuclear state. The expected duration of crisis in such asymmetric directed dyads is substantially smaller than the duration of crisis for actors in nonnuclear dyads. Nuclear actors in asymmetric dyads are also more likely to prevail than states in symmetric nuclear dyads.