Or is it from inbreeding? Well, yes, it is from imperialism, somewhat, but the inbreeding part gives imperialists a moral high ground. It’s kind of like how the slower minds of Africans gave slavers and segregationists a moral high ground.
Bottom line: you don’t want to be weak in a battle against your enemies. But that’s not justifying the enemy.
Moral High Ground and Advantage
Also, not forgetting the advantage. Of course, the strong will conquer the weak – and since some places are savaged by mental illness and low IQ – then how much easier they are for evil minds to exploit!