Anyone who has done even a little reading about the theory and practice of war— whether in political theory, international relations, theology, history, or common journalistic commentary—has encountered a sentence of the form “War is horrible, but . . . .” In this construction, the phrase that follows the conjunction explains why a certain war was (or now is or someday will be) an action that ought to have been (or still ought to be) undertaken, notwithstanding its admitted horrors. The frequent, virtually formulaic use of this expression attests that nobody cares to argue, say, that war is a beautiful, humane, uplifting, or altogether splendid course of action and therefore the more often people fight, the better.
From the foregoing commentary, a recurrent theme may be extracted: those who argue that “war is horrible, but . . .” nearly always use this rhetorical construction not to frame a genuinely serious and honest balancing of reasons for and against war, but only to acknowledge what cannot be hidden—that war is horrible—and then to pass on immediately to an affirmation that notwithstanding the horrors, whose actual forms and dimensions they neither specify nor examine in detail, a certain war ought to be fought.
If someone demands that the skeptic about war offer constructive criticism, here is my proposal: always insist that the burden of proof rests heavily on the warmonger .. If they cannot—and I submit that they almost never can—then people will serve their interests best by declining an invitation to war. As a rule, the most rational, humane, and auspicious course of action is indeed to give peace a chance.