The killer lives in shadows, a phantom menace whose whereabouts are known only to a few trusted deputies. He exhorts followers to seek martyrdom in suicidal assaults against U.S. soldiers, Iraqi policemen and Christian churchgoers even as he remains perpetually on the run, seeming to abandon hideouts just as his pursuers arrive. Intelligence analysts say that before U.S. forces chased Abu Mousab al-Zarqawi out of the city of Fallujah, he would call lieutenants from a cell phone and then trash the SIM card after a single use to avoid giving himself away. So obscure is his identity, so ghostly his purported lifestyle, that even some who have joined al-Zarqawi's campaign against U.S. troops and their Iraqi allies question whether his accomplishments are mostly myth. "We have not felt the existence of al-Zarqawi," says insurgent leader Abu Lina, a top nationalist commander. "We haven't known him or understood him." But to a devoted few, his word is absolute. "Some just have to sit and listen to him," a senior insurgent leader in Fallujah told TIME, "and they walk away committed."
In the past year, that commitment has helped produce an almost daily horror show of suicide bombings, kidnappings, mass executions and televised beheadings. The atrocities have killed or maimed thousands, jeopardized next
month's elections, dragged Iraq to the brink of civil conflict and drawn U.S. troops deeper into a war whose costs seem increasingly unbearable. Ascribing the mayhem in Iraq entirely to al-Zarqawi and his minions would overlook both U.S. miscalculations and the scope of the insurgency, which may command the support of as many as 20,000 Sunnis. But through his capacity for self-promotion and the sheer ruthlessness of his methods, al-Zarqawi, 38, has become the face of an insurgency fueled as much by religious zealotry as by nationalist resistance. He has catapulted himself from a fringe player on the global terrorist stage to its most potent operative, a villain judged by U.S. intelligence to be so dangerous that the bounty on his head now matches Osama bin Laden's.
Al-Zarqawi's aims seem clear: in messages intercepted by the U.S. military and in public statements posted on websites associated with his organization, formerly known as al-Tawhid and Jihad, al-Zarqawi has voiced his contempt for Iraq's majority Shi'ites and his desire to provoke a civil war by slaughtering those perceived to be collaborating with the U.S. or the fledgling Iraqi authorities. In a July al-Tawhid document obtained by TIME, al-Zarqawi's former deputy, Abu Anas al-Shami, refers to the group's assassination of Ayatullah Mohammed Baqir al-Hakim, one of the most prominent Shi'ite leaders in Iraq, in an August 2003 bombing in Najaf. Al-Zarqawi has lured hundreds of zealots, foreign and homegrown, to join him by portraying Iraq as the new arena of global jihad, the proving ground for an epic war against the infidel. He pledged his allegiance to bin Laden in October in a Web announcement but has cultivated a global profile of his own, forging links with terrorist cells across Europe and the Middle East. An audiotape made in the summer and given to TIME records al-Shami saying the group's goal is to turn Iraq into a fundamentalist state modeled on the Taliban's rule, whose primeval strictures for Afghanistan al-Zarqawi has admired. (Al-Shami was killed in September in a U.S. bomb attack.)