In the "Gender and Islam" course that I took a few years ago at Columbia University, the professor made what many might consider a provocative point: Western criticism of female genital mutilation and honor killings is hypocritical and a form of racism. While she lectured, two young women sitting in the front row—one in a spaghetti-string tank top with green hair and several piercings and the other conservatively dressed and wearing a hijab—snapped their fingers in approval. At the time, I wondered why these women, living in the United States and so different on the outside, were so quick to...