U.S. Defense Secretary Leon Panetta waves as he boards his plane at Kandahar Airfield in Kandahar, Afghanistan, Thursday, Dec. 13, 2012. Panetta visited with troops and had meeting with commanders during his visit. (AP Photo/Susan Walsh, Pool)

Photo by: Susan Walsh

U.S. Defense Secretary Leon Panetta waves as he boards his plane at Kandahar Airfield in Kandahar, Afghanistan, Thursday, Dec. 13, 2012. Panetta visited with troops and had meeting with commanders during his visit. (AP Photo/Susan Walsh, Pool)