think of every large scale fight by armies ever. They are fighting US vs them. Why do we do this if we are naturally homophilic?
If the world were as you say, then when fighting for land, the two sides who view themselves as different would break down and share the land because "there differences don't really matter". This has never happened because it's human nature.
The differences matter because certain people would like certain laws that restrict many, or invite
harsh treatment.
The differences are really impacting things, unlike skin colors.
INB4 you say the cultures that the skin colors signify, I'd rather you realize
Africans have been separated from their homeland loong ago, and that I don't
know a single African tradition I've ever practiced that came from Africa.
I think these culture differences you speak of is just the difference between
people with [more likely] poor education and are in poverty, against people with [more likely] better
education and income.
War isn't sparked by minor differences.. if that was the case, we'd always be in it
considering no country is 100% the same.