Secretary of Defense James N. Mattis arrives at the Tomb of the Unknown Soldier during the 150th Presidential Armed Forces Full Honor Wreath-Laying Ceremony at Arlington National Cemetery in Arlington, Va., May 28, 2018. The ceremony, held to honor the America’s fallen service members, began after a 21-gun cannon salute announced the president’s arrival and was followed by the national anthem, the wreath-laying, the playing of “Taps,” and a moment of silence. (U.S. Air Force photo by Staff Sgt. Jordyn Fetter)