Why did we lose North Africa?
North Africa (Carthage) Colonized by Phoenicians, who, as I understand it, (maybe) were South-Caucasian (South East Black Sea) > Iranian > Semitic > ~Bahrain? Yemen? (jews/yemeni origin?) In other words, they were cousins of then-North africans (theselves of the Iranian distribution)
Carthage, like Sicily, and Crete before it, was in an exceptionally good trading position and far from the high costs of defense in the fertile crescent.
Carthage was an advanced civilization superior to Rome, and culturally similar to what we imagine in greece. If Athens and Sparta were analogous to London and Germany, then Carthage was analogous to Paris.
Due to trade conflicts (that were probably unnecessary), Rome destroyed Carthage (justifiably in my opinion), weakening north Africa west of the Nile. (exaggeration maybe).
The primary damage to rome was the combination of population dilution (over-immigration), inadequate institutions for the scale (failure to develop fiat money in particular), the failure to convert from a slave to a serf and to freemen economy (largely again because an inability to develop soft money), the destruction of celtic civilization resulting in the german invasions, and therefore an inability to resist the germanic hordes. However the substantial crisis (in my view) was the Justinian Plague (the first visitation of the plague upon europe). The second was the conquest by Constantine. And the final blow was the exhaustion of the byzantines against the Persians that weakened the ancient civilizations such that the Turks (who had been kicked out of northern china), and the Arabs (who were no different from the Germans in effect) could occupy and incrementally destroy the advanced civilizations, from which neither Persia, Byzantium, The Levant, and North Africa can recover. And from which the peoples of the steppe may never progress.
In my view the semites, both Jewish and Arab are perhaps an innovation upon earlier versions of man simply by virtue of aggression. WHile the jews adopted the feminine strategy, the arabs adopted the masculine, and these two extremes seem to be extremely effective against the moderate peoples of China/Japan/Korea/India, and the north iranians (persians), and the north (europeans of all delineation).
We will, within a century, decode the genes for low IQ and high aggression, but hopefully we will domesticate (by force) the semitic peoples before either extreme is able to do further damage to mankind.