Pre-flight checks are conducted prior to a B-1B Lancer launch from Ellsworth Air Force Base, S.D., May 19, 2020, in support of a Bomber Task Force mission within the U.S. European Command area of responsibility. BTF missions are a visible demonstration of the United States’ capability of extended deterrence and commitment to the collective defense of the NATO alliance. (U.S. Air Force photo by Airman 1st Class Christina Bennett)