Vagrant recollections after seeing Captain Phillips, which might win yet another Academy Award for Tom Hanks, should win for Barkhad Abdi and surely ought to win one for Paul Greengrass (sensational filming, nothing like it). It is said that Ibn Khaldûn, fourteenth-century Arab scholar, was the first to notice and describe cycles in history--and in particular to note how "desert" populations (think Genghis Khan or Mohammed) may rise up and conquer "settled" peoples, only to be supplanted by other desert peoples in their turn.
Since desert life no doubt is the source of bravery, savage groups are braver than others. They are, therefore, better able to achieve superiority and to take away the things that re in the hands of other nations. The situation of one and the same group changes, in this respect, with the change of time. Whenever people settle in fertile plains and amass luxuries and become accustomed to a life of abundance and refinement, their bravery decreases to the degree that their wildness and desert habits decrease.
This is exemplified by dumb animals, such as gazelles, wild buffaloes, and donkeys, that are domesticated. When they cease to be wild as a result of contact with human beings, and when they have a life of abundance, their vigor and violence undergo change. This affects even their movements and the beauty of their coat. The same applies to savage human beings who become sociable and friendly.
The reason is that familiar customs determine human nature and character. Superiority comes to nations through enterprise and courage. The more firmly rooted in desert habits and the wilder a group is, the closer does it come to achieving superiority over others, if both (par tires) are proximately equal in number, strength, and group feeling.
In this connection, one may compare the Mudar with the Himyar and the Kahlân before them, who precede them in royal authority and in the life of luxury, and also with the Rabî'ah who settled in the fertile fields of the 'Irâq. The Mudar retained their desert habits, and others embarked ion a life of abundance and great luxury before they did. Desert life prepared the Mudar most effectively for achieving superiority. They took away and appropriated what the other groups had in their hands.--So Ibn Khaldûn, The Muqaddimah 107 (Franz Rosenthal Trans., 2005). Thomas Barfield gives a modern account along similar lines in The Perilous Frontier (1992) his history of nomadic peoples along the northern border of China. Last I knew, there were statues of Ibn Khaldûn in Cairo and Tunis, and his face was/is on the Tunisian 10 dinar note.