Williams had a hunch about terrorist groups and flight schools, and that hunch on its own would not have been enough to prevent the attacks of September 11. But dismissing it on those grounds fundamentally misses the point. Williams stumbled across a provocative and surprising idea that was nonetheless incomplete. But if that hunch had connected with another equally provocative idea, one that emerged three weeks later and five hundred miles away, the Phoenix memo might well have transformed the history of the early twenty-first century.
