POWER SHIFT Defense Secretary Robert M. Gates thanks Gen. Peter J. Schoomaker, 35th U.S. Army chief of staff, in a ceremony honoring his service at Fort Myer, Va., April 10, 2007. Schoomaker will transition responsibility to Gen. George W. Casey, Jr., who is set to become the next Army chief of staff. SHARE: Download: Full Size (0.02 MB) Credit: VIRIN: 395812-C-NLV30-481.jpg Photo Gallery