A KC-135 Stratotanker from Royal Air Force Mildenhall, England, lands at Rovaniemi Air Base, Finland, May 17. Personnel and aircraft from RAFs Mildenhall and Lakenheath deployed to bases in Finland and Sweden for Arctic Challenge 2017, a multinational training exercise aimed at maintaining the relationships and trust essential for ensuring regional security. (U.S. Air Force photo/Airman 1st Class Abby L. Finkel)