“Total war is the demand of the hour,” Goebbels declared in 1943, speaking in a stadium below a vast banner that read “Totaler Krieg—Kürzester Krieg” (“Total War—Shortest War”). Even twenty-first-century armies have taken this to heart. In the late two-thousands, the Sri Lankan military, after fighting Tamil separatists at a low pitch for a quarter century, attacked rebel strongholds in full force and killed as many as forty thousand civilians, burning the bodies or burying them in mass graves. The war never resumed. The campaign, or what it represented, became known as “the Sri Lanka Solution.”

As Moyn points out, the idea that war should be unrestrained has drawn support not just from battle-hardened officers but even from self-proclaimed pacifists. Foremost among them was Leo Tolstoy, who had served in the Russian Army during the Crimean War and in the Caucasus. Tolstoy disdained the Red Cross, and believed that making war more humane could make war more likely. In “War and Peace,” the vessel for Tolstoy’s views was Prince Andrei, who had been wounded while fighting Napoleon’s Army at Austerlitz: “They talk to us of the rules of war, of chivalry, of flags of truce, of mercy to the unfortunate and so on. It’s all rubbish! . . . If there was none of this magnanimity in war, we should go to war only when it was worthwhile going to certain death.” If Moyn doesn’t quite endorse this view, he’s gripped by its modern implications. In particular, he believes that the American way of war, as it has evolved in our century, has become precisely what Tolstoy feared: so prettified as to be wageable everywhere, all the time.