U.S. Defense Secretary Ash Carter, center back, meets with NATO Secretary General Jens Stoltenberg at NATO headquarters in Brussels, Oct. 8, 2015. Carter is on a five-day trip to Europe to attend the NATO Defense Ministerial in Brussels, and meet with counterparts in Spain, Italy and the United Kingdom. DoD photo by U.S. Army Sgt. 1st Class Clydell Kinchen