Two Polish air force ceremonial guardsmen salute each other during a wreath-laying ceremony at the Tomb of the Unknown Soldier in Warsaw, Poland, June 22, 2015. Deborah Lee James, Secretary of the U.S. Air Force, completed a visit of installations through Europe June 24, 2015, to meet Airmen, community leaders and allied and partner nation defense chiefs. (U.S. Air Force photo by Staff Sgt. Joe W. McFadden/Released)