SECURITY DISCUSSIONS U.S. Defense Secretary Robert M. Gates, left foreground, and U.S. Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, right foreground, listen to opening remarks by visiting Gen. Xu Caihou, right, vice chairman of the Central Military Commission, Chinese People's Liberation Army, during security discussions at the Pentagon, Oct. 27, 2009. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 619156-S-NTL76-325.jpg Photo Gallery