Secretary Gates speaks with outgoing acting U.S. Central Command commander Lt. Gen. John Allen. Secretary of Defense Robert M. Gates speaks with outgoing acting U.S. Central Command commander Lt. Gen. John Allen (right) and incoming commander Gen. James N. Mattis before an assumption of command ceremony at MacDill Air Force Base, Fla., on Aug. 11, 2010. SHARE IMAGE: Download Image: Full Size (0.06 MB) Photo By: VIRIN: 689209-N-QQQ85-236.jpg Photo Gallery