President Barack Obama, Vice President Joe Biden and Defense Secretary Leon Panetta react to chairman of the Joint Chiefs of Staff Adm. Mike Mullen's remarks during the Chairman of the Joint Chiefs of Staff change of responsibility ceremony at Summerall Field, Joint Base Myer-Henderson Hall, Va., Sept. 30, 2011. Mullen was succeeded by Army Gen. Martin E. Dempsey, the18th chairman of the Joint Chiefs of Staff, during the ceremony. President Barack Obama, Vice President Joe Biden and Defense Secretary Leon Panetta react to chairman of the Joint Chiefs of Staff Adm. Mike Mullen's remarks during the Chairman of the Joint Chiefs of Staff change of responsibility ceremony at Summerall Field, Joint Base Myer-Henderson Hall, Va., Sept. 30, 2011. Mullen was succeeded by Army Gen. Martin E. Dempsey, the18th chairman of the Joint Chiefs of Staff, during the ceremony. SHARE IMAGE: Download Image: Full Size (3.43 MB) Tags: Photo Essays Photo By: VIRIN: 274652-X-GDL89-871.jpg Photo Gallery