A Marine with the 31st Marine Expeditionary Unit's Maritime Raid Force posts security aboard a simulated non-compliant vessel during Visit, Board, Search and Seizure training at Marine Corps Base Hawaii, Kaneohe Bay, Hawaii, Jan. 14, 2019. (Cpl. Isaac Cantrell/Marine Corps)
The Arleigh Burke-class guided-missile destroyer USS Donald Cook (DDG 75) transits the Bosphorus Strait on Jan. 19, 2019, en route to the Black Sea. (MC2 Ford Williams/Navy)
A B-2 Spirit bomber deployed from Whiteman Air Force Base, Mo., conducts aerial refueling Jan. 15, 2019, near Joint Base Pearl Harbor-Hickam (JBPHH), Hawaii, during an interoperability training mission. (Master Sgt. Russ Scalf/Air Force)
An Army National Guard soldier fires his M4 carbine during weapons qualifications on Joint Base McGuire-Dix-Lakehurst, N.J., Jan. 13, 2019. (Master Sgt. Matt Hecht/Air National Guard)
Aviation Boatswain’s Mate (Handling) 1st Class Natalia Fraser signals to an AH-64A Apache helicopter Jan. 7. 2019, on the flight deck of the amphibious transport dock ship USS Arlington (LPD 24) in the Mediterranean Sea. (MC2 Brandon Parker/Navy)
Marines fire an M2 .50-caliber Browning machine gun during a defense of the amphibious task force gunnery exercise Jan. 20, 2019, aboard the amphibious assault ship USS Wasp (LHD 1) at sea. (Lance Cpl. Kyle P. Bunyi/Marine Corps)
Paratroopers fire their M119 Howitzer on Jan. 10, 2019, certifying their capability to shoot accurately in a timely and safe manner at Joint Base Elmendorf-Richardson, Alaska. (Sgt. Alex Skripnichuk/Army)
Senior Airman Alec Leavitt, Airman 1st Class Nick Burns, and Master Sgt. Ken McElroy, 104th Munitions Flight ordnance mechanics, prepare to conduct a 60 day inspection on a Captive Air Training Missile 9X-2 on Jan. 16, 2018, at Barnes Air National Guard Base, Mass. (Airman 1st Class Randy Burlingame/Air National Guard)