Admittedly, there is something futile, even ridiculous, about philosophers stepping forward to offer dispassionate critical judgments about the topic of war. For one thing, war is waged today by the colossus of the modern state, bristling with weapons and armaments, some of which now possess apocalyptic power. Philosophical analysis and argument can seem an absurdly mismatched David when pitted against this monstrous Goliath. For another, war is often waged under conditions of extreme stress. As such, it is both cause and symptom of some of the darkest human impulses – fear, violence, hatred, suspicion, and the desires to inflict harm, to humiliate, to terrorize, to destroy, or to avenge. These potent human motivations have little place in, and are, alas, rarely influenced by, intellectual reflection of any kind.

But to picture war as simply a mindless orgy of violence would also be misleading. Wars are fought for reasons, sometimes even for the sake of moral ideals, and not usually waged on impulse alone. They are often initiated as a result of cool strategic calculation on the part of statespeople who claim, quite conscientiously and dispassionately, to be duty bound to pursue the national interest. War is also an institution as much as a collective manifestation of personal aggression. Soldiers often recognize and abide by written and unwritten conventions and codes of conduct. War is conducted by complex organizations – the armed forces – structured by elaborate rules of authority and deference, and characterized by a very distinctive professional ethos.