Leading from the front: 3/6 Marines train to become small unit leaders - A Marine with 3rd Battalion, 6th Marine Regiment, 2nd Marine Division ejects a spent round from an M203 40mm grenade launcher during a Tactical Small Unit Leaders Course at Camp Lejeune, N.C., Jan. 16, 2017. The 10-day course provides small unit leaders with the confidence, knowledge and ability to effectively lead Marines in combat situations. The course aimed to make the Marines team leaders and increase proficiency with various weapon systems and tactics so they can mentor their Marines and become a more effective team. (U.S. Marine Corps photo by Cpl. Aaron Henson)

U.S. Army Soldiers with Alpha Company, 2-501st Parachute Infantry Regiment, fire an 81mm mortar in support of the Afghan National Army during operation Maiwand 10 in Helmand Province, Afghanistan, Dec. 26, 2017. The Soldiers fired multiple illumination rounds in order to light a nearby area of Marjah where the ANA experienced a nighttime ambush. (U.S. Marine Corps photo by Sgt. Justin T. Updegraff) - U.S. Army Soldiers with Alpha Company, 2-501st Parachute Infantry Regiment, fire an 81mm mortar in support of the Afghan National Army during operation Maiwand 10 in Helmand Province, Afghanistan, Dec. 26, 2017. The Soldiers fired multiple illumination rounds in order to light a nearby area of Marjah where the ANA experienced a nighttime ambush. (U.S. Marine Corps photo by Sgt. Justin T. Updegraff)