Months after Karen Hughes assumed the role of diplomat-at-large to the Muslim world, she told Time magazine that one of her two key influences on understanding Islam was Georgetown Prof. John Esposito. She’s not alone. The FBI has repeatedly consulted him, and much of academia holds him in high regard. But when he’s not busy shaping U.S. policy toward the Muslim world, Prof. Esposito mentors a man who wishes he could be a suicide bomber and who recently (and publicly) reinforced his support for “martyrdom.” He has collaborated on two books with Dr. Azzam Tamimi, and he still maintains a...