Just cycling back to a previous post, the ME isn't just divided by religion, but also by ethnicity. Arabs, Turks, Persians, Kurds, Armenians, Copts and an host of smaller minorities rub shoulders, and also have centuries old divisions and hatreds. Suni Turks won't be particularly fond of Suni Kurds, for a well known example, while Bedouin Arabs look down on their Palestinian "brothers".
Lining up "sides" for this version of the 30 years war isn't going to be nice and neat at all. For a bit of fun, you might take some talc and start drawing overlays of ethnic and religious groups on a political map of the ME. Spice it up with some economic overlays to see where large pools of resources that can be used for warfighting (or coveted by their neighbours) lay. Now look at a geographic overlay to see where natural "redoubts" exist, giving certain groups shelter and much more breathing space than others.
That should provide a nice introduction to why the next generation is going to be so "interesting" in the Chinese sense.