This paper proceeds from a sense of dissatisfaction with much of current moral argument about defence policy, in particular the role of nuclear weapons. Discussions of the moral issues tend to divide into two distinct kinds of writing: on the one hand, impassioned calls to action based on and allied with equally impassioned moral exhortations; and on the other hand, usually in academic contexts, meticulous analyses and comparisons of aspects of nuclear policy with paradigm cases of acknowledged moral categories or requirements, with the object of showing by analogy with these that the particular aspect of policy under discussion is or is not morally wrong. My unease is caused by the fact that, while it is difficult not to respond to the impassioned style of argument, as one recognizes in it a practical and moral urgency which our situation seems to demand, nevertheless it plainly appeals only to those already convinced of its conclusions. The unconverted tend to regard it with suspicion or disdain, for in contrast to the analytical style, which manifestly seeks to compel the intellect, the impassioned style seems to make its effect by stirring the emotions as much as if not instead of by compelling the intellect. On the other hand the analytical style can seem curiously irrelevant, even trivial, in relation to the issue. For instance, it has been argued that since: nuclear war is a moral disaster; deterrence is threatening or intending to wage nuclear war; it is wrong to threaten or intend to do something wrong; therefore: deterrence is wrong, and should be abandoned. It is hard to believe that defenders of deterrence as the cornerstone of defence policy are going to be persuaded by such an argument to abandon their advocation of it, if only because the argument totally ignores the object of deterrence.