Interesting article some time back in the Naval Institute Proceedings--the author argued that Arab civilization is in the midst of a collapse, and gave a bunch of metrics to support his thesis.
Arab civilization may be in the middle of collapse, but Islam has spread far beyond the Arab world. Even in the Middle East you have the Iranians who are Persian not Arab. Also not Arab are the large Muslim populations of Pakistan, Bangladesh, and Indonesia, to name a few.
An important factor in the Protestant Reformation struggles was that dissenting groups had American to move to. Large numbers of religious "refugees" came here from Germany, Scotland, England, and Ireland. The ultimate conclusion was that the only way we could have a free country was for us to have universal FREEDOM OF RELIGION. These people had suffered the worst ravages of intolerance, and fortunately our leaders had the good sense to decide to leave religion out of politics. What Islam will do with the same fighting and intolerance we have yet to see.
They do not have a wide open frontier to escape to as existed in the Seventeenth and Eighteenth Centuries. Will they ever learn that the only way for multiple interpretations of the same, or different religions to survive in a country is to have RELIGIOUS FREEDOM? Unfortunately, it doesn't look like this is going to happen any time soon. I just hope we can manage to keep our t.. out of the wringer while all this is going on.