"Will not perhaps the temporal power of Islam return and with it the menace of an armed Mohammedan world, which will shake off the domination of Europeans -- still nominally Christian -- and reappear as the prime enemy of our civilization? The future always comes as a surprise, but political wisdom consists in attempting at least some partial judgment of what that surprise may be. And for my part I cannot but believe that a main unexpected thing of the future is the return of Islam".
-Hilaire Belloc, 1938
Yeah, you've probably seen it before, but I like it.