U.S. Marines with 2nd Intelligence Battalion and British soldiers search for a checkpoint during Exercise Phoenix Odyssey II near Edinburgh, U.K., Oct. 30, 2015. The service members executed a three-mile conditioning hike and shooting competition as part of the exercise, which is designed to enhance joint intelligence operations. (U.S. Marines Corps photo by Cpl. Lucas Hopkins/Released) - U.S. Marines with 2nd Intelligence Battalion and British soldiers search for a checkpoint during Exercise Phoenix Odyssey II near Edinburgh, U.K., Oct. 30, 2015. The service members executed a three-mile conditioning hike and shooting competition as part of the exercise, which is designed to enhance joint intelligence operations. (U.S. Marines Corps photo by Cpl. Lucas Hopkins/Released)

A British soldier addresses U.S. Marines and other soldiers during Exercise Phoenix Odyssey II in Edinburgh, U.K., Oct. 27, 2015. The two-week exercise is designed to enhance joint intelligence operations between the two nations. (U.S. Marine Corps photo by Cpl. Lucas Hopkins/Released) - A British soldier addresses U.S. Marines and other soldiers during Exercise Phoenix Odyssey II in Edinburgh, U.K., Oct. 27, 2015. The two-week exercise is designed to enhance joint intelligence operations between the two nations. (U.S. Marine Corps photo by Cpl. Lucas Hopkins/Released)