MENA was great for civilization back in the day, slaves to own, resources to plunder. I imagine that if you placed one of these 'barbarians' as a baby in a greek or roman household they would fit in perfectly well. It's just the excess afforded by slavery and untapped riches that allows for these amazing civilizations and especially their great architectural works.
Building civilization came with a price: the coal tax. They all eventually mixed to some degree. Many greeks and italians are white, but plenty of them are quite mixed.
The 'barbarians' had a lifestyle that worked for them, most importantly it prevented them from mixing. Until now, where they ship nonwhites into every white nation