U.S. Secretary of Defense Ashton B. Carter walks from plane with official greeting party Dec. 5, 2016 upon arrival to Yokota Air Base, Japan. Carter stopped at Yokota during his travel to U.S. military instillations across the world, with plans to thank deployed U.S. troops for their service over the holidays. (U.S. Air Force photo by Airman 1st Class Donald Hudson/Released)