The UK Bomber Command in WW2 had a strategy of "area bombing" - which was basically to hit the centre of German cities because they were easy to find and to hit at night. There were lots of euphemisms used e.g. "dehousing" - but everyone knew that it was a policy of targeting civilians.
Of course, the UK was on the winning side, so no war crimes trials.
http://en.wikipedia.org/wiki/Bombing_of_Dresden_in_World_War...
I can only assume (my father died several years ago) that he felt somewhat ashamed of his time in the war. I didn't appreciate the negativity surrounding the bombing campaigns until more recently when they opened the memorial in Hyde Park corner in London (http://www.rafbf.org/1794/bomber-command-memorial.html). It's difficult to appreciate this when you grow up watching films like the Dambusters and 633 Squadron and seeing these guys as heroes. Dads are always heroes.