U.S. Defense Secretary Ash Carter shakes hands with Republic of Korea soldiers during a visit to the Demilitarized Zone, in the Republic of Korea, Nov.1, 2015. Carter is visiting the Asia-Pacific region, where he will meet with leaders from more than a dozen nations to help advance the next phase of the U.S. military’s rebalance in the region by modernizing longtime alliances and building new partnerships. Photo by Air Force Senior Master Sgt. Adrian Cadiz