A U.S. Air Force Airman prepares to fuel a F-15C Eagle prior to the morning launch at Starokostiantyniv Air Base, Ukraine, Oct. 10 as part of the Clear Sky 2018 exercise. This exercise is an example of continued U.S. engagement promoting stability in the region. Exercises like this increase participating nations' capacity to conduct a full spectrum of military operations. (U.S. Air National Guard photo by Tech. Sgt. Charles Vaughn)