Once again humans are self domesticated animals. Every so often some group of humans get together and create a 'tribe' that think they are more superior than all the other tribes. (ie.. bombing on 9-11, Hitler, Imperial Japan, ....... Genghis khan, Roman Empire....). Than human animal's emotions take over and the other human tribes become less domesticated. While the 'wild' animal trait can be suppressed or crushed for a few years, nothing will change.
But there is one thing that will stop it...... if you watched the 1951 movie "The Day the Earth Stood Still" they talk about how all civilized planets got together and created a population of robots. The robots had one purpose- to stop all acts of violence of one planet against another .... by elimination.