Proposed approach to evaluate the deterrence of limited nuclear attacks

A counterforce strategy intends to destroy an adversary’s nuclear arsenal. However, hardening, defences and mobility have made nuclear-delivery systems less vulnerable. Nations may consider limited attacks with one or a few weapons that would not significantly deplete their weapon stockpile or alter the overall nuclear balance. We propose an approach to evaluate limited strikes with regard to military, political, economic and societal aspects. We discuss potential responses along with their compliance to the Law of Armed Conflict (LOAC). We contend that a response should be generally proportional, meaning sufficient to achieve deterrence in the hope of avoiding escalation. Responses that greatly exceed the attacker’s inflicted damage will be perceived as unjust and, if executed, may escalate the conflict. Similarly, declared responses that inflict considerably less damage may not be sufficient to deter since the attacker would end the initial exchange in a better relative position between the adversaries. We conclude that deterrence is improved with a range of nuclear capabilities. Countries limiting responses to only military targets based on a strict interpretation of the LOAC may not have a viable response to deter some types of limited nuclear attacks.