An E-4 carrying Defense Secretary Jim Mattis lands at Osan Air Base, Republic of Korea, Feb. 2, 2017. The visit, which is Mattis’ first official visit to a foreign country as secretary of defense, highlighted the common traits and strengths shared by the U.S. and ROK governments, including the commitment to bi-lateral cooperation in keeping regional safety and stability in check. (U.S. Air Force photo by Staff Sgt. Jonathan Steffen)