Megan McArdle argues that the war crimes of the past (firebombing Dresden) cannot justify the war crimes of the present (torture.) I agree, wholeheartedly, something I didn't think I'd write. The idea that grampa had to butcher thousands in order to win, so what's a little waterboarding, is pretty retarded.
But she quotes Frederick Taylor's book on Dresden... and Taylor more-or-less argues that Dresden's symbol as a war crime has been abused by all and sundry, and that in a number of ways Dresden was as legitimate a target as any in WWII. That's a hell of a qualifier, in my books, but his point is basically that if you're going to yell about Dresden, you need to yell about all of aerial bombardment throughout that period.
There's also the point that the aerial destruction of Germany was, if anything, way more justifiable than torturing every other Muslim male we round up. This doesn't make it right in an objective sense, but consider at least one fact, that German artillery deployments were massively reorganized to protect Germany on the "third front" -- the skies -- which inarguably kept artillery tubes from facing advancing armies on the other two fronts throughout 1944 and 1945.
Like I said, not exculpatory for the Allied air offensive, but at least a tangible strategic benefit from the air war. Compare this to torture, which has exactly zero tangible evidence of success, and the gang of sadists in charge at the White House make Bomber Harris look positively humane.