PBS FRONTLINE: THE INSURGENCY 2 OF 3

PBS FRONTLINE: THE INSURGENCY PART 2 OF 3

Baathist loyalists who had fought for Saddam made up the initial resistance to coalition forces. "Before, I carried my weapon as an officer in the Iraqi army against the Americans," says Abu Mohammed, a senior leader within the Iraqi nationalist branch of the insurgency. "So it is natural I would fight the Americans now. The resistance is a natural reaction to any occupation."

Slowly, however, Baathist groups ran low on funding. This provided an opening for Abu Musab al-Zarqawi and other foreign fighters, who used lots of cash and an Islamic ideology persuasive to some Iraqis to increase their influence.

Ghaith Abdul-Ahad, an Iraqi photojournalist who has risked his life to report on the foreign fighters in Iraq, provides unique insight into their mindset. In Fallujah, he met an insurgent from Yemen just days before the U.S. and Iraqi forces attacked the city. "This guy would sit and would tell me about his family back in Yemen," says Ghaith. "He would tell me about his wife, … his children and the young daughter that he loves very much. And then … he would dismiss this: 'Oh no, no -- this is the devil trying to tempt me away from my jihad.'"

"The Insurgency" goes to the city of Tal Afar shortly after it is retaken by U.S. and Iraqi troops to document the brutality inflicted there by Al Qaeda in Iraq. The insurgents had utilized the northwestern city as a staging post for equipment and reinforcements brought in through Syria and had terrorized the local population. "They killed [my brother]. They cut his stomach open and put bombs inside," says one resident. "They left him by the roundabout next to the petrol station. My father wanted to go and pick his body up. They blew up my father."