  Although less prominent as a topic now than it was before the collapse of the Soviet Union, a large and useful philosophical literature has developed around the questions of the justice and efficacy of various strategies for avoiding both nuclear war as well as subjection to nuclear blackmail/extortion. The questions here are tremendously difficult to address sensibly, in part because the stakes of the policies and decisions at issue are so high and novel that they are almost beyond comprehension. Although nuclear threats appear superficially to be similar in structure to ordinary coercive threats, several facts set them apart. For one thing, the morality and rationality of such threats are significantly more complicated than in most ordinary cases of coercion. As Gregory Kavka puts it, there's a “paradox of deterrence” which holds that it is potentially morally proper to threaten to use MCWs even though it is arguably immoral to actually use them for any reason (including in executing that threat) (Kavka 1978). This violates a plausible principle that holds that it is wrongful to intend to do what it would be wrongful to do (the “wrongful intentions principle”). Moreover, even though it may be morally proper to threaten such use, Kavka argues that no rational, morally motivated person could form the proper intention needed to make a credible threat of such use. Subsequent writers have argued over whether in fact these paradoxes hold as Kavka suggests. (See, e.g., Dworkin 1985; Wasserstrom 1985; Kroon 1996.) The moral issues in deterring nuclear war and the use of MCWs more generally are of central importance, and depend little if at all on our understanding the nature or ethics of coercion, per se (Hardin 1986). But, looking in the other direction, issues around deterrent threats involving MCWs do tell us some things about the nature of coercion.