Defense Secretary Jim Mattis meets with Army Gen. John W. Nicholson Jr., right, commander of NATO's Resolute Support mission, in Kabul, Afghanistan, April 24, 2017. Navy Rear Adm. Craig S. Faller, the secretary's senior military assistant, and Sally Donnelly, the secretary's senior advisor, participated in the meeting. DoD photo by Air Force Tech. Sgt. Brigitte N. Brantley