The events of September 11, 2001, were unique in American history, public tragedies so overwhelming that they altered not just the politics of the nation, but its entire cultural consciousness. Nearly five years later, the political consequences of that day are apparent, if far from resolved. The cultural effects, however, are just beginning to take shape. From a host of mediocre novels to TV shows like 24 and The Sopranos, the lingering effects of that day have brushed up against our popular culture. But until recently, the day itself remained sacrosanct, as artists and critics have struggled with how one...