Yeah there’s lots of kinds of Christianity too. I get that they hate each other but they’d fall in line to the superpower or they’d get dealt with.Except that there's no monolithic Islam. That whole Sunni/Shia split makes it impossible. Iran (Shia) and Saudi Arabia (Sunni) hate each other as bad if not worse than they hate us or the West. Hell, just look at what they're doing to each other in Syria. And all you have to do is look at the civil war and how the lines were drawn in Iraq after the overthrow.
Mind you this would take 50 years to pan out. But nothing else has worked.