Jim Pinkerton has a straight-forward thesis at TCS about the formation of regional religio-cultural blocs around the world - the Western/Christian, the Chinese/Confucian, the Indian, etc. The caliphate aspires to be one of them. A quote:
So regional blocs, based on a common characteristic, such as religious and cultural ancestry, are naturally powerful. And of course, if one country is the leader of such a bloc, it doesn’t want a rival within that bloc to emerge -- and thus it can’t be displeasing to American strategists that the European Union is foundering. Just as Europeans were once eager to keep the rest of the world divided, so we should not lament the failure of a Brussels-based superstate to emerge as much more than a costly red-tape dispenser. America is effectively unchallenged within the Christian Bloc.
But there’s a problem dead ahead: As we look around the world, we can see that other countries are forming blocs of their own, too. China, for example, is pulling together a Confucian bloc in East Asia. The People’s Republic is an empire of its own, people-wise and territory-wise, but it is now using its longer and longer politico-economic hook to reel in as many of its neighbors as it can.
It makes sense. And, as I see it, it's a post-imperial development, since it is no longer necessary to "own" another nation to make money trading with it. It's the new version of Ye Olde Power Game. Read the whole thing here.