I agree, I have studied history a lot, it is one of my favorites. There is that saying that those who don't know the evils history are cursed to repeat it.
But my view is very simple. Just apply morals to it. For example if you have a "leader" that has slaughtered tens of thousands of people.
Well I don't care how you spin that, you can't make him to be a righteous man. There is just no justification for genocide, it's utterly evil. And anyone who tries to justify it, is an accomplice.
So how could those events been settled throughout history? I don't know, but there was always a solution that didn't involve murder. But they have always ignored that.
Just read Chomsky how he points out that in the Cold War the US ignored every single peace proposal from the Soviets and instead pushed further with war. Well that is that.
So there is always a peaceful decent solution, and we must always seek to choose this one instead of the evil one.
There is no way I could have said it better! :)