Marines prepare and execute training during Steel Knight 20 (SK20) at Marine Corps Air Ground Combat Center, Twentynine Palms, Calif., on Dec. 2, 2019. (Lance Cpl. Benjamin Aulick/Marine Corps) 
A KC-135 Strato Tanker refuels an F-16 Fighting Falcon Dec. 7, 2019, over South Dakota. (Capt. Ramah Husidic/Air Force) 
U.S. Army UH-60 Black Hawk helicopter crew-chief scans the horizon during a 20 multi-ship air assault to the Pohakuloa Training Area on the Island of Hawaii, Nov. 11, 2019. (Spc. Geoff Cooper/Army) 
President Donald Trump throws the coin before the start of the Army-Navy college football game in Philadelphia, Saturday, Dec. 14, 2019. (AP Photo/Jacquelyn Martin) 
Marine Corps Lance Cpl. Zachary Cooper, a radio operator, uses the AN/PRC-117 Multiband Manpack Radio to set up communication during exercise Steel Knight (SK20) at Marine Corps Air Ground Combat Center Twentynine Palms, California, Dec. 5, 2019. (Cpl. Alexa M. Hernandez/Marine Corps) 
Aviation Electrician’s Mate 2nd Class Trevor Brewster, left, and Aviation Electrician’s Mate 3rd Class Caleb Byers run diagnostics on the weapons system of an F/A-18F Super Hornet on Nov. 20, 2019, in the hangar bay of the aircraft carrier USS Theodore Roosevelt (CVN 71) in the Pacific Ocean. (Mass Communication Specialist Seaman Olympia O. McCoy/Navy) 
Marines participate in an amphibious landing and assault through a combat town on Red Beach during Steel Knight 20 at Marine Corps Base Camp Pendleton, Calif., Dec. 6, 2019. (Lance Cpl. Angela Wilcox/Marine Corps) 
Coast Guardsmen assigned to Maritime Safety Response Team (MSRT) West prepare to be hoisted up from the deck of aerial target launch ship (ATLS 9701) onto an MH-60S Sea Hawk helicopter on Nov. 12, 2019, while conducting helicopter visit, board, search and seizure training operations off the coast of San Diego. (Mass Communication Specialist 2nd Class Ryan M. Breeden/Navy) 
Two F-22 Raptors fly over Joint Base Pearl Harbor-Hickam, Hawaii, Dec. 5, 2019. (Airman 1st Class Erin Baxter/Air Force)
