Winter-safe Deterrence: The Risk of Nuclear Winter and Its Challenge to Deterrence

Abstract

A new line of nuclear winter research shows that even small, regional nuclear wars could have catastrophic global consequences. However, major disarmament to avoid nuclear winter goes against the reasons nuclear weapon states have for keeping their weapons in the first place, in particular deterrence. To reconcile these conflicting aims, this paper develops the concept of winter-safe deterrence, defined as military force capable of meeting the deterrence goals of today's nuclear weapon states without risking catastrophic nuclear winter. This paper analyses nuclear winter risk, finding a winter-safe limit of about 50 nuclear weapons total worldwide. This paper then evaluates a variety of candidate weapons for winter-safe deterrence. Non-contagious biological weapons (such as anthrax or ricin), neutron bombs detonated at altitude, and nuclear electromagnetic weapons show the most promise. Each weapon has downsides, and the paper's analysis is only tentative, but winter-safe deterrence does appear both feasible and desirable given the urgency of nuclear winter risk.