That might be right, and goes to show just how much damage the misguided ideology and policies of a few proletarians waging war on "elite establishment" can do.
But that was just one, short historical period that did massive amounts of damage. I think Europeans "win" overall when you factor in the many independent instances of death and mayhem inflicted, especially on others.
But don't get me wrong. Unlike the OP, I don't think white Europeans or any other race is inherently more violent than others. Europeans have been so destructive because they had the power to dominate. Others would and have done the same, which is evident across all of history.
And the same thing with black people in the US. I don't think they are inherently more violent. Perhaps they are more violent, but the causes lie in poverty, discrimination and lack of perspectives. Factor in US gun culture and you get what you bargain for.