While the destruction of the World Trade Center and the strike against the Pentagon shocked the world at large, experts on terrorism like Walter Laqueur couldn't feign complete surprise.
In No End to War, Laqueur, who has devoted three decades to the study of political violence, answers the most-often raised questions about terrorism in the light of 9/11 and the still unsolved Anthrax letters.
First, what constitutes terrorism? What...