Abu Musab al-Zarqawi

Abu Musab al-Zarqawi, birth name Ahmad Fadeel al-Nazal al-Khalayleh, began his life as a violent, petty criminal in Zarqa, Jordan. Having embraced fundamentalist Sunni Islam, as encouraged by his mother to curb his lawbreaking, Zarqawi (literally, "the man from Zarqa") came to embrace jihad against non-Muslims, Shiites, and even insufficiently devoted Sunnis as a way of embracing his new piety along with his fundamentally violent nature. After brief stints in Afghanistan fighting its socialist government in the early 1990s and then in a Jordanian prison for a terror plot, Zarqawi eventually settled in Iraq just prior to the U.S. invasion in 2003.

After the U.S. invasion ousts long-time dictator Saddam Hussein, Zarqawi began carrying out terror attacks designed to hinder the reconstruction of the country, and also targeted Shiites in an effort create conflict between the two major sects of Islam in Iraq. His...