Bin laden himself spoke of ensuring that "the pious Caliphate will start from Afghanistan." His chief deputy, Ayman al-Zawahiri, also dreamed of re-establishing the caliphate, for then, he wrote, "history would make a new turn, G-d willing, in the opposite direction against the empire of the United States and the world's Jewish government." Another Al-Qaeda leader, Fazlur Rehman Khalil, publishes a magazine that declares "Due to the blessings of jihad, America's countdown has begun. It will declare defeat soon," to be followed by the creation of a caliphate. Or, as Mohammed Bouyeri wrote in the note he attached to the...