Laos and Cambodia weren't participants in the war but that doesn't really feel like it matters all that much. Whenever I talk about the bombings of Cambodia and Laos with Americans (who - liberals and conservatives alike feel they must always defend) I sometimes here "well we bombed cities in Germany and Japan in WW2 and no one talks about those being war crimes". But were they? I really don't know much about those bombings. My gut says yes they were also war crimes but we just accept them because they were combatant countries?
From what I know about Dresden: it was horrific, there was an intentional plan by the allies to target working class neighborhoods. They were near industry, giving plausible deniability, they were densely populated, increasing casualties and the morale hit, and the theory as usual was that there would be civil unrest. What's also true is that the damage was exaggerated by Nazi propaganda at the time, which has actually made it difficult to estimate the casualties caused by the bombings.
I'm assuming this isn't going to be particularly controversial, I'm cribbing from a WWII dad-doc I saw on Netflix, so I assume it's pretty standard and accepted stuff.