SWEARING IN Defense Secretary Robert M. Gates addresses the audience during a swearing-in ceremony for Army Gen. Martin E. Dempsey on Fort Myer, Va., April 11, 2011. Dempsey was sworn in as the 37th chief of staff of the Army succeeding Army Gen. George W. Casey, Jr., who has retired. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 702994-B-XGF89-703.jpg Photo Gallery