The U.K., the United States, and Canada have been among the countries ramping up their Arctic military exercises, and for the past five years, photographer and film-maker Louie Palu has been taking pictures of soldiers confronting an environment as hostile and deadly as any enemy force. He has photographed a parachute drop into mountainous terrain in Alaska, "through-the-ice" training in a lake in the Northwest Territories, a submarine coming up from under the ice in the Beaufort Sea, and igloo-building and radar operations in Nunavut. He saw soldiers suffer frostbite and, during exercises in Finland, even be killed in a vehicle accident, he said.