If there's one man on this list whose ideas are having a real-world impact, it's Sayyid Imam al-Sharif, sometimes known as Dr. Fadl. He's hardly a household name in the West. But among violent jihadists, this 59-year-old Egyptian inmate -- one of al Qaeda's founders and one-time mentor to Ayman al-Zawahiri -- is viewed as a turncoat, a back-stabber, and a liar. In a remarkable series of prison writings renouncing violence and attacking al Qaeda on Islamic theological grounds, Sharif has done more to expose the terrorist group's obscurantism and hypocrisy than almost anyone else.
Sharif came of age within the crucible of modern jihadism: Egypt in the 1970s. Along with Zawahiri, he studied to be a doctor at Cairo University's Faculty of Medicine. The two became close friends, and Sharif soon joined Zawahiri's group al-Jihad. After the 1981 assassination of Egyptian President Anwar Sadat and subsequent crackdown on all jihadi cells, both became wanted men.
Sharif managed to slip out of Egypt, temporarily resettling in Saudi Arabia. Zawahiri was not so lucky and faced several hard years in Egyptian prison. The pair later regrouped on the front line of the jihad against the Soviet occupation of Afghanistan, where Sharif developed a reputation among the mujahideen as a serious jihadi scholar with an encyclopedic knowledge of Islamic jurisprudence. Zawahiri, discredited for having revealed his terrorist accomplices to Egyptian authorities and demoralized by prison, ceded the reins of al-Jihad to Sharif in 1987.
They had the big ideas that shaped our world in 2009.
During this period Sharif completed two key texts, The Essential Guide for Preparation and The Compendium of the Pursuit of Divine Knowledge. Essential Guide, published in 1988, inserted a steel rod into the jihadi backbone. His ultra-extreme definition of jihad, focused exclusively on martyrdom and eternal warfare, made even the godfather of global jihadism, Abdullah Azzam, wince. Despite lingering reservations from certain jihadi corners, Essential Guide quickly became a new legal compass for the global movement.
The 1989 Soviet withdrawal from Afghanistan allowed al-Jihad to turn its focus back on the Egyptian government. But the relationship between Zawahiri and Sharif soured. Sharif had grown tired of al-Jihad's repeated operational failures and legal missteps in Egypt. In 1993, Sharif turned command of al-Jihad back to Zawahiri and officially resigned from the leadership. Their final break came over Sharif's most rabid work, Compendium.
Compendium expanded the definition of what constituted a disbeliever in jihadi ideology. Not only could Arab governments be found guilty of disbelief, but now, according to Compendium, anyone who willingly adhered to those rulers and their laws was damned. Anyone who voted in elections or participated in any way in the advancement of a government that was not under Islamic law ought to be slain.