SHARING A LAUGH U.S. Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, and his wife, Deborah, enjoy the USO Holiday Tour on Bagram Airfield, Afghanistan, Dec.15, 2010. The Mullens are hosting the tour featuring comedians Robin Williams, Lewis Black and Kathleen Madigan, Tour de France champion Lance Armstrong, and country music artist Kix Brooks in the Central Command area of responsibility. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 523266-X-CYO21-645.jpg Photo Gallery