islamic state," the first step toward a global caliphate. >> he was never content just to be the thug from zarqa, and he wasn't content just to be the guy who beheaded nick berg. he wanted to rule a caliphate. >> narrator: it was something bin laden hadn't yet pushed for. >> al-qaeda saw that time as a long way off, and zarqawi was very, very much more impatient. he said, "this we can do now." >> allahu akbar! >> narrator: for zarqawi, the creation of the caliphate would be the fulfillment of a prophecy. >> that religious vision promises the return of god's kingdom on earth, the reestablishment of the early islamic empire, the empowerment of sunni muslims around the world. that the reestablished caliphate will eventually take over the entire globe, and then the entire world will come crashing to an end. >> the lead aircraft is goingo engage it here momentarily with a 500-pound bomb on the target. >> narrator: the next video the world would see of zarqawi was very different. (explosion) in 2006, the u.s. military received a tip and bombed zarqawi's hideout. >> the terrorist whose forces set off so many... >> narrator: zarqawi was dead. but his call for an isla