WESTMINSTER WALK U.S. Defense Secretary Leon E. Panetta, left, tours the Palace of Westminster with Andrew Robathan, minister of state for the U.K.'s armed forces, in London, Jan. 18, 2013. Panetta is on a six-day trip to Europe to visit with defense counterparts and troops. SHARE: Download: Full Size (0.08 MB) Credit: VIRIN: 947534-H-NXN92-330.jpg Photo Gallery