The sad truth is, they have more to fear from us (a post-Christian "Western" civilization founded in materialism/hedonism) than they do from the Muslims.
The old story plays out again. Byzantium didn't fall to the Turks until it had first been sacked and mortally wounded by Christian crusaders.
The only consolation for Christians is Jesus' promise that the gates of hell will not prevail against his church--though I'm beginning to think that the church to which He refers is in every individual heart that remains faithful to Him.