NUCLEAR REVIEW Left to right, Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, Defense Secretary Robert M. Gates, Secretary of State Hillary Clinton and Energy Secretary Steven Chu conduct a press conference to discuss the Nuclear Posture Review at the Pentagon, April 6, 2010. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 978458-Z-PDW66-955.jpg Photo Gallery