In this essay, I propose five principles to make U.S. nuclear deterrence policy more just and effective in the future: sever the link between the mass killing of innocent civilians and nuclear deterrence by focusing targeting on adversaries’ military power and senior political leadership, not their population; never use or plan to use a nuclear weapon against any target that could be destroyed or neutralized by conventional weapons; reject “belligerent reprisal” threats against civilians even in response to enemy attacks on one's own or allied civilians; replace nuclear “calculated ambiguity” threats against biological or cyberattacks with “deterrence by denial” strategies; and work in good faith toward eventual nuclear disarmament.

Any threat to use nuclear weapons inherently carries the possibility of escalation to a level such that both parties in a conflict, and likely many others, would be destroyed. Yet nuclear weapons are also seen as necessary for securing the very things that would be destroyed if the weapons were ever used. The fix for this nuclear dilemma relies on the strategy of deterrence. Deterrence provides a rationale for why nuclear weapons are necessary, even though they may seem dangerous. But the practice of deterrence involves less intentionality and agency than is usually assumed. The success of deterrence relies partially on luck as well as unrealistic assumptions about human behavior. Rather than a strategic necessity, deterrence may be an institutionalized behavior, accepted because it has always been practiced rather than because it makes sense. Assessing the ethics of deterrence and nuclear weapons requires engaging with these issues.