When he succeeded his father in 1999, King Abdullah of Jordan released a batch of political prisoners in the hopes of smoothing his transition to power. Little did he know that among those released was Abu Musab al-Zarqawi, a man who would go on to become a terrorist mastermind too dangerous even for Al-Qaeda and give rise to an Islamist movement bent on dominating the Middle East. Zarqawi began by directing hotel bombings and assassinations in Jordan from a base in northern Iraq, but it was the American invasion of that country in 2003 that catapulted him to the head of a vast insurgency. By identifying him as the link between Saddam and bin Laden, the CIA inadvertently created a monster. Like-minded radicals saw him as a hero resisting the infidel occupiers and rallied to his cause. Their wave of brutal beheadings and suicide bombings continued for years until Jordanian intelligence provided the Americans with the crucial intelligence needed to eliminate Zarqawi in a 2006 airstrike....