The enormous amount of ethnicities and languages in the countries of Sahara contributed to mainly bad and unwanted things to be happening. In lots of the countries there's big devidence between the ethnic groups and it is not unusual that they have clashes that very often have devastating consequences. The countries of the southern half of Sahara usually have clashes on daily basis and there's open hatred and violence between the different ethnic groups, which also leads to the governments having enormous difficulties in the control of some regions. In the northern half of Sahara there has been a systematic genocide going on for quite some time that is kept behind the curtains, like the example with the Barbers and the Jews of North Africa whose numbers have been significantly falling down and they have been massacred systematically by other groups.
The Egyptians failed to adapt to the new changes of their world. There are multiple books on this and it is very interesting.
