This is precisely the discussion to have to avoid these atrocities. Many religions and ideologies preserve a "perfectly pure" picture of themselves but only when you start to dig in the past you discover things of which we should be less proud of. We cannot be guilty for whatever happened before we were born, but we certainly can remember it to say "stop" when similar things happen during our lifetime.
@kravietz @farhan Yes, as I said history matters.. it can be an important context but in of it self a pissing contest rarely lead to anything. I don't really care what ideology or faith the perpetrator have.. that rarely matters. Those are often just adapted for the perpetrators needs.
What we need is a more powerful international court. That can indict people from any country. Not that I think this will happen anytime soon.