Chairman's Signature U.S. Marine Corps Gen. Joseph F. Dunford Jr., chairman of the Joint Chiefs of Staff, signs a guest book at the president's residence in Irbil, Iraq, Oct. 20, 2015. DoD photo by D. Myles Cullen SHARE: Download: Full Size (0.37 MB) Credit: D. Myles Cullen VIRIN: 151020-D-XT155-002.JPG Photo Gallery