Secretary of Defense Ash Carter meets with United States Ambassador to the United Kingdom Matthew Winthrop Barzun on Oct. 9, 2015. Carter is on a five-day trip to Europe to attend the NATO Defense Ministerial Conference in Brussels and to meet with counterparts in Spain, Italy, and the United Kingdom. (DoD photo by U.S. Army Sgt. 1st Class Clydell Kinchen) (Released)