It is the phrase of the moment, dropping from the lips of television reporters and radio commentators, salting the columns of pundits, earnestly being spoken by furrow-browed politicians of serious mien. The families of the fallen are entitled to war-weariness. So are those wounded in body or spirit, and their loved ones. The mother who has sent her son to war has a right to war-weariness, as does the father who prepares to send his daughter to battle again and again. But for the great mass of the American public, for their leaders and the elites who shape public opinion,...