U.S. Secretary of Defense Ashton Carter visits U.S. service members at Morón Air Base, Spain, Oct. 6, 2015. During his visit, Carter thanked the service members for their hard work and emphasized the importance of strategic transition in today’s changing global security environment. - U.S. Secretary of Defense Ashton Carter visits U.S. service members at Morón Air Base, Spain, Oct. 6, 2015. During his visit, Carter thanked the service members for their hard work and emphasized the importance of strategic transition in today’s changing global security environment.