Unity through common enemies

I have to agree with Ed Brayton that bringing religions together may not be so delightful as we'd like to think. In the US, Catholics and Protestants have found they can cooperate just fine, thank you, if they both want to hurt the same people ("You hate gays, too? I thought I was the only one!"). Nothing unites people like having a common enemy and the vision of Christians and Muslims uniting in jihad/crusade against everyone else should give us nightmares. Serious, wake-up-in-the-middle-of-the-night-shaking-in-
horror-and-the-sheets-soaked-with-sweat nightmares.