Pentagon Briefing Defense Secretary Dr. Mark T. Esper and Chairman of the Joint Chiefs of Staff Army Gen. Mark A. Milley brief the media at the Pentagon, Dec. 20, 2019. SHARE: Download: Full Size (0.5 MB) Tags: Chairman, Milley, Defense Secretary, Esper Credit: Marine Corps Sgt. Warren Smith, DOD VIRIN: 191220-D-MG926-022C.JPG Photo Gallery