Abstract

Many people have misgivings about the strategy of nuclear deterrence. Some of those misgivings centre on issues of effectiveness: safety depends entirely upon the dissuasion of an adversary. Other misgivings centre on moral concerns: the essence of deterrence is the threat, and the conditional intention, to kill millions of noncombatants. US President Reagan's Strategic Defence Initiative promised an alternative to deterrence, a strategic posture of interception of an adversary's weapons rather than preclusion of the decision to attack. It is conceived as a means of ‘defending’ the United States that does not threaten anyone. In this essay I examine various SDI proposals. I argue that only one of these could justify the transition to a strategic posture of ‘defence’, and might be a genuine alternative to deterrence—the one that is least feasible technologically. Only that one could plausibly be claimed to be morally superior to deterrence—and for strategic reasons, even its claim is dubious at best. Technologically more feasible proposals are not ‘defences’, but variants of deterrence. Since that is so, the most common and dramatic claim of their moral superiority to deterrence is incoherent.