One of my struggles as a self-declared decent person is the tug between my intellectual abhorrence of Islam and my response at a personal level when I see Muslim women walking about with their hair hidden under hijabs. I would never insult or belittle such women to their faces, and I would treat them with courtesy and respect. But I can’t help but think that at some point, there might be so many hijabs walking around that we stand in real danger of being forced to submit to sharia law. We would have to look the other way as Islam’s...