Pre-Saharasian period of peaceful "garden" conditions was real, with human violence appearing only with long-term epochs of drought-famine-starvation-migration, and then sometimes disappearing generations later after rains returned.

Once re-created by new patrist institutions, armoring and violence are then independent of desert-geography or nutrition! It can then be carried out of the desert by the new warrior-nomads, who conquer, kill and enslave other cultures, and transplant their social institutions into new territories.