PATRICE GREANVILLE—The clamor about four Americans recently killed in Syria reeks of infantile petulance: what do you expect when you send soldiers into battle zones? Some professions have built-in risks. Ask any firefighter. Yet this response—used, as noted elsewhere, to make Trump walk back his promise to get the US troops out of Syria—is only too typical of American discourse. The ugly fact is that for a variety of reasons, none too healthy or honorable, the American people have been conditioned to believe in fighting endless wars with practically no casualties, or a ratio of losses so absurdly small when compared to the enemy’s that every casualty is mourned indignantly, as if the targets of American meddling had no right to inflict any punishment on our legions.