the most visible sign of that transition was in march of 2004, which is what's called first fallujah. the battle of first fallujah. it was insurgency. and zarqawi was leading it. >> fallujah exploded when four contractors were ambushed. killed. their bodies were burned and mutilated. one of them was my old operations sergeant in the rangers. the bodies were hung famously from the traffic bridge, and there were people dancing in the streets. there were young children holding pieces of american bodies almost like you'd wave around a lollipop. the first thing you feel is just rage. you feel frustration. you want to get in and solve the problem. >> they want to kill innocent life. to try to get us to quit. we're not going to. and our military commanders will take whatever action is