[N]o Allied commander would have sent his troops into Hamburg with orders to machine-gun thirty-seven thousand of its inhabitants. It would unquestionably have been a war crime. But Allied aircraft killed just that number in July 1943, and there has never been even the merest suggestion that those who ordered the raid ought to have stood trial after 1945 (though there is now a widely held view that this was a war crime). Indeed, bombing killed hundreds of thousands in horrible ways. What made this kind of airpower different?Overy hints at a few stale rationalizations, from the all-justifying horrors of the Nazi regime to the absurd suggestion that civilians were not expressly targeted by the bombing campaigns, to which the very psychological-philosophical foundations of Douhet's own airpower theory gives the lie.
So: how is it that William Calley is so reviled for the killing of 22 Vietnamese civilians while Harry Truman is largely forgiven for the killing of perhaps 200,000 Japanese civilians? Why is tactical atrocity punished while strategic atrocity is applauded?