For the past decade and a half, my family has reacted to every terrorist attack with a special kind of anxiety.

Setting aside any concern about falling victim to an explosion, we cross our fingers and speculate creatively on the identity of the perpetrator. Perhaps, this time, it was simply a white paranoid schizophrenic. Or maybe a laid-off gun nut with no release valve for his rage. Or, better yet, a run-of-the-mill neo-Nazi who would direct public indignation in an appropriate direction.

Regrettably, the perpetrators of these attacks often turn out to be Muslims. The ensuing phone conversations with my parents — secular Pakistani immigrants whose piety does not extend beyond a distaste for pork — revolve around admonitions to be careful what streets I walk on and to avoid arguments with white people.