In reference to Krikkit's ideas with the whole Muslim pope thing, uh, yeah...
There's no reason for them to form such a denomination, because if I remember correctly Shiite Islam (based mainly in Iran) is already centralized to a degree around such a notion and Sunni Islam, which the majority of Muslims worldwide follow, is decentralized and they have no intention of centralizing power around any specific figure any time soon because of the wide distribution of Muslims worldwide (with the largest Muslim population in the world being in Indonesia, of all places) and no real predominant Muslim power. Even when the caliphates existed, the caliphs mainly dealt with secular matters leaving religion to the scholars (even though their rule was justified by religion) so there was no real combination of political and religious power in one figure like the Roman Catholic Pope or the Orthodox Ecumenical Patriarch. The powers of both can be traced to the political structure, or an imitation of the political structure, of the Roman Empire, and the caliphates lacked this connection.
Also the major powers of the present haven't exactly collapsed it seems, they are just much weaker. If they had we wouldn't have Americans celebrating the launch in the trailer. Even though the American faction seems to be represented by a corporation, there must be an "America" for them to represent to call themselves the "American Reclamation Corporation".