The problem with the assumption that a caliphate is likely is that it a caliphate means absolute control by a caliph. One man, which means all other ambitious men in the caliphate must submit to his rule.
I content that Muslims have in recent years provided absolutely zero evidence that formation of such a state is likely. Quite to the opposite, the various groups contending for power are more likely to result in smaller and less cohesive states than larger combinations.
All Islamists proclaim the desirability of a caliphate. But every one of their leaders sees himself as the caliph. Not a recipe for unity.
