Milley Speech Chairman of the Joint Chiefs of Staff Army Gen. Mark A. Milley, speaks during a change-of-command ceremony at Peterson Air Force Base, Colo., Aug. 20, 2020. Air Force Gen. Glen D. VanHerck succeeded Air Force Gen. Terrence J. O'Shaughnessy as the commander of the North American Aerospace Defense Command and U.S. Northern Command. O'Shaughnessy is retiring from active duty after 34 years of military service. SHARE IMAGE: Download Image: Full Size (0.52 MB) Tags: Milley, Chairman Photo By: DOD Video Still VIRIN: 200820-O-ZZ999-003C.JPG Photo Gallery