My understanding is that Dresden was primarily a cultural center, with little or no impact on the war effort, so I think that the firebombing of Dresden was wrong.
My understanding is that a lot of the production of war materials in Japan was spread out among the neighborhoods, so that it was not possible to separate them. Whether it was necessary to bomb as widely as was done there, I just don't know.
World War II was very much a war against civilians, and those who argue in favor of preferring civilian targets by Palestinians or anyone else is in effect arguing for a return to the bad old days. I can only hope that they do not succeed in convincing nations with major military power that preferring civilian targets is OK, because if they do, the term "blood lust" will achieve a whole new and horrible meaning.