Many of you will know of Freeman Dyson as a world-class physicist. But he was also assigned to RAF Bomber Command during World War II. Here are his thoughts on bombing of urban areas, from Disturbing the Universe:
At the beginning of the war, I believed fiercely in the brotherhood of man, called myself a follower of Gandhi, and was morally opposed to all violence. After a year of war, I retreated and said, Unfortunately nonviolent resistance against Hitler is impracticable, but I am still morally opposed to bombing. A couple of years later I said, Unfortunately it seems that bombing is necessary to win the war, and so I am willing to work for Bomber Command, but I am still morally opposed to bombing cities indiscriminately. After I arrived at Bomber Command I said, Unfortunately it turns out that we are after all bombing cities indiscriminately, but this is morally justified, as it is helping to win the war. A year later I said, Unfortunately it seems that our bombing is not really helping to win the war, but at least I am morally justified in working to save the lives of the bomber crews. In the last spring of the war I could no longer find any excuses.