PALACE EXCHANGE Colombian Defense Minister Gabriel Silva, U.S. Defense Secretary Robert M. Gates, center right, and U.S. Ambassador to Colombia William R. Brownfield talk to one another at the Presidential Palace before meetiing with President Alvaro Uribe in Bogota, April 15, 2010. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 468925-B-NOS29-462.jpg Photo Gallery