United States Forces Korea and Republic of Korea air force leaders wait for Defense Secretary Jim Mattis to deplane at Osan Air Base, Republic of Korea, Feb. 2, 2017. Mattis’ visit to the ROK, the first such visit in his tenure as secretary of defense, comes in light of a year of strong provocations from North Korea, affirming the ironclad commitment the U.S. has in strengthening its robust alliance with the ROK. (U.S. Air Force photo by Staff Sgt. Jonathan Steffen)