I feel like this is whataboutism but I also feel like civilisation 80 years ago was way less advanced in terms of human rights and everything so in my mental model war crime 80 years ago was lesser crime than it is today. But of course it's wrong to think like that - war crime is a war crime.
Let's not forget that we British deliberately killed German civilians in WW2 https://www.theguardian.com/world/2003/oct/22/worlddispatch.germany#:~:text=Around%20600%2C000%20German%20civilians%20died,perished%20in%20a%20vast%20firestorm.