Esper Remarks Defense Secretary Dr. Mark T. Esper speaks during the change of command ceremony for U.S. Northern Command and North American Aerospace Defense Command at Peterson Air Force Base, Colo., Aug. 20, 2020. SHARE IMAGE: Download Image: Full Size (6.11 MB) Tags: NORAD, Northern Command, Defense Secretary, Esper Photo By: Thomas Paul, DOD VIRIN: 200820-O-JS470-794A.JPG Photo Gallery