I think we all start out pretty ignorant and tribal. Then we learn to, as Douglas Adams put it, "bang the rocks together." Where we go beyond this may not be so straightforward. But with fire, agriculture, wheels, we go further and longer. And some of us call it 'civilization'. Some tribes appear to get ahead of the others, and credit themselves as superior because of it. A book called "Guns, Germs and Steel" attempted to put it in perspective.

I think it is wrong to persecute people for things they cannot help. You shouldn't kill them and enslave them just because you can. But it is also human nature to exploit the weakness of other humans.

You shouldn't blame people for all your current problems because of things their parents may have done to your parents. The past is not fully knowable, and what little we know of it indicates everyone has base human drives and everyone is liable to blame the other guy.

Europe was colonized and invaded and hard done by. And the religious wars continued the utter viciousness of the worst of human nature to play out well into historical times.
America was colonized and invaded.
Asia was colonized and invaded. I'd say China has a good case to be really ticked off at the British because they were pretty civilized by anyone's standards for a long period of time before being subjected to the twin activities of the Missionary and the opium trade. But does that justify China's current bellicosity and anti-environmental activities in Africa, and the South China Seas? I'd say it doesn't justify it but it maybe explains it.

Africa had a long time of human habitation before being colonized, had its own wars and genocides and territorial occupations. Then was colonized in parts but has seen plenty of inter-tribal violence, both before and after European involvements, which was caused by pure old human culpability.

Some of the things that stand out are King Leopold's outright destruction and thievery and Rwanda's Hutu-on-Tutsi genocides, and the current outrages in South Sudan. But Europe had PLENTY of those types of outrages over centuries.

Face it. We've had a planet-full of BAD PARENTING. Everyone's got an attitude.

We should be thankful that in the present world there is an overall decline in world violence.