FILE - In this June 8, 2008, file photo, a U.S. soldier at a press conference in Baghdad, Iraq, takes down an older photo, to display a latest image purporting to show the body of Abu Musab al-Zarqawi, an al-Qaida-linked militant who led a bloody campaign of suicide bombings, kidnappings and hostage beheadings in Iraq. After al-Zarqawi's death in a 2006 U.S. airstrike, his Iraqi successor, Abu Omar al-Baghdadi, began to bring in more Iraqis, particularly former Saddam Hussein's officers. That process was accelerated when Abu Bakr al-Baghdadi took over after his predecessor was killed in a 2010 airstrike. (AP Photo/Khalid Mohammed, File)