Recently, Al Qaeda experts have been questioning the ties between Zarqawi and Osama Bin Laden, arguing that the two men are linked but far from close allies.
Hear about the man who's likely behind the latest horrors in Iraq.
Michael Ware, Baghdad correspondent for Time Magazine
Steven Simon, senior analyst at the RAND Corporation, former senior director of counterintelligence at the National Security Council, author of "The Age of Sacred Terror: Radical Islam's War Against America"
Rohan Gunaratna, author of "Inside the al Qaeda Global Network of Terror," head of terrorism research at the Institute of Defense and Strategic Studies in Singapore.
This program aired on September 23, 2004.