Emperor-of-New-Zealand
Kicked
I guess a better question then is whether Islam is necessary as the catalyst, or whether the tribes could unite around something else, whether religious or not.As mentioned in my post prior, Islam served as the catalyst for the unification of Arab tribes, without some sort of equivalent social movement/unifying faith akin to Islam serving as a factor for the tribes to coalesce around. The tribes proved remarkably competent in taking advantage of the power vacuum within the Middle east and North Africa, and had many extremely capable warriors amongst their ranks, yet pre-Islam were disunited and were plagued by feuds and rivalries. Islam brought about a revolutionary change in which it transcended pre-existing social norms to create a radically different society, uniting the Arabs under a concept of brotherhood. Therefore without some sort of Islam-like movement to unite the tribes under a singular interest, such expansion would be unlikely.