ASSUMPTION OF COMMAND U.S. Marine Corps Gen. James N. Mattis, incoming commander of U.S. Central Command, right back, takes the flag signifying his assumption of command from Marine Corps Lt. Gen. John R. Allen, outgoing, acting commander, center, while Defense Secretary Robert M. Gates looks on during a ceremony on MacDill Air Force Base, Fla., Aug. 11, 2010. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 234217-J-QNN05-245.jpg Photo Gallery