A soldier in Basic Combat Training with Company C, 1st Battalion, 61st Infantry Regiment, tosses a practice grenade into a bunker on the hand grenade assault course at Fort Jackson, S.C., Feb. 1, 2016. (Brian Hamilton/U.S. Army)

U.S. soldiers of 2nd Squadron, 2nd Cavalry Regiment provide security while defending an attack position during exercise Allied Spirit IV at the U.S. Army's Joint Multinational Readiness Center at Hohenfels Training Area, Germany, Jan. 31, 2016. (Seth Plagenza/U.S. Army)

Soldiers with 2nd Squadron, 2nd Cavalry Regiment attack simulated enemy combatants while conducting a defense operation during exercise Allied Spirit IV at the U.S. Army?s Joint Multinational Readiness Center at Hohenfels Training Area, Germany, Feb. 2, 2016. (Randy Wren/U.S. Army)

Pfc. Tristan Lehman, AH-64 Apache helicopter repairer with 122nd Aviation Support Battalion, 82nd Combat Aviation Brigade, works to remove the radar altimeter to prevent damage when loading the helicopter into U.S. Air Force aircraft, at Fort Bragg, N.C., Feb. 2, 2016. (Christopher Freeman/U.S. Army)

Soldiers of Mortar Platoon, Headquarters and Headquarters Troop, 3rd Squadron, 2nd Cavalry Regiment react to a 60mm high explosive mortar round being fired during mortar training and evaluation at Adazi Training Area, Latvia, on Feb. 3, 2016. (Jennifer Cruz/U.S. Army)

Sgt. 1st Class James Austin, an instructor with the Medical Battalion Training Site, 166th Regiment, Regional Training Institute, Pennsylvania Army National Guard, assists Sgt. Todd Turner, 155th Chemical Battalion, Ohio National Guard, with bandaging a wound on role-playing patient Spc. Shane Hines, 118th Infantry Regiment, South Carolina National Guard during training at Fort Indiantown Gap, Pa., Feb. 3, 2016. (Angela King-Sweigart/U.S. Army)

Sgt. Maj. of the Army Daniel Dailey speaks to soldiers at the 10th Mountain Division Sustainment Brigade after running with them Feb. 4, 2016. Dailey made his first trip to 10th Mountain Division and Fort Drum, Feb. 3 and 4. (Kap Kim/U.S. Army)

A soldier with the 97th Military Police Company shoots oleoresin capsicum, or pepper spray, into the face of a simulated assailant during a law enforcement competition on Fort Riley, Kan., Feb. 1, 2016. (Hannah Kleopfer/U.S. Army)