U.S. Defense Secretary Ash Carter, his wife, Stephanie, and Army Lt. Gen. Sean MacFarland speak with troops in Baghdad, Dec. 16, 2015. Carter thanked the troops for their service and sacrifice, especially during the holiday season. MacFarland is in charge of the coalition fighting the Islamic State of Iraq and the Levant, or ISIL. DoD photo by Army Sgt. 1st Class Clydell Kinchen