Eugene Armstrong and Jack Hensley, the two Americans who were beheaded this week in Iraq, are just the latest victims in a series of kidnappings, beheadings, murders, suicide bombings and other acts of terrorism that have been attributed to 37-year-old Jordanian terrorist Abu Musab al-Zarqawi. He is said to run the most violent terror network among the many in Iraq. But who is he, and what are his beliefs? Full Story