by Todd Gitlin

About the author: Todd Gitlin, author of several books on media and society, is a professor of journalism, culture, and sociology at New York University. As president of Students for a Democratic Society in 1963, he helped to organize the first national demonstration against the Vietnam War.

As shock and solidarity overflowed on September 11, 2001, it seemed for a moment that political differences had melted in the inferno of Lower Manhattan. Plain human sympathy abounded amid a common sense of grief and emergency. Soon enough, however, old reflexes and tones cropped up here and there on the left, both abroad and at home—smugness, acrimony, even schadenfreude, accompanied by the notion that the attacks were, well, not a just dessert, exactly, but . . . damnable yet understandable payback . . . rooted in America’s own crimes of commission and...