The thing with South Africa is that it is probably the only country in the world that has a more complicated history of Whites & Blacks than our own. I'm not excusing what has been done to whites in South Africa since apartheid, but Apartheid was sick. Check out Trevor Noah's story. His birth was a crime. Paul Simon's most successful album ever, Graceland, was recorded in South Africa during Apartheid & the hoops he had to jump through compare nothing to the hoops that the black musicians on the album had to jump through. When you oppress & suppress a group of people systematically, you've got to expect violent disturbing repercussions for years to come (often centuries). And its not limited to race. Read A Tale of Two Cities or Les Miserables. We're astounded at the atrocities committed in Africa, but European history is every bit as disturbing when you delve into it. The longer & stronger the oppression, the more explosive & violent the turnaround.
Atrocities happen when a group feels they are 1 - Justified in exacting retribution on a class of people because of wrongs done to them by others in that class, or 2 - Justified in keeping an "inferior" class of people beneath them based on some kind of perverse divine right. Both are sick, and both feed into a vicious cycle.
Every war if you ask me can be traced to these two basic premises.