FORT MCNAIR WELCOME U.S. Army Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, welcomes Mexican leaders army Gen. Salvador Cienfuegos Zepeda, defense secretary, and navy Adm. Vidal Francisco Soberón Sanz, navy secretary, for the U.S.-Mexico Defense Chiefs Strategy Dialogue at the National Defense University on Fort McNair in Washington, D.C., July 15, 2013. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 383245-K-FUZ28-177.jpg Photo Gallery