A U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)

View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)

Star Wars collector James Burns, 44, poses for a photograph with some of his collection in London December 2, 2015. He said “I've met so many wonderful people, all over the world. It's a wonderful community of likeminded people with an interest in Star Wars. There's nothing else like it”. (Photo by Paul Hackett/Reuters)

A Pasola rider reacts after throwing his spear during the Pasola war festival at Ratenggaro village on March 22, 2014 in Sumba Island, Indonesia. The Pasola Festival is an important annual event to welcome the new harvest season, which coincides with the arrival of “Nyale” sea worms during February or March each year. Pasola, an ancient ritual fighting game, involves two teams of men on horseback charging towards each other while trying to hit their rivals with “pasol” javelins and avoid being hit themselves. (Photo by Ulet Ifansasti/Getty Images)

Throughout the course of the long war in Afghanistan, Coalition troops have relied on thousands of military working dogs to help keep them safe, and make their jobs easier. The dogs are trained to detect explosives, to find illegal drugs, to search for missing comrades, or target enemy combatants. Not only are they active on the front lines, but behind the lines they serve as therapy dogs, service dogs, and loyal companions. They also share the same risks as the ground troops, suffering injuries and sometimes death on the battlefields. Gathered here are images of these dogs and their handlers in Afghanistan and back home, from over the past several years, part of the ongoing series here on Afghanistan.

A suspected street robber is arrested by a policeman after a brief chase in the streets, June 20, 2016, in Manila, Philippines. The president-elect of the Philippines, Rodrigo Duterte, declared a war on crime and drugs after sweeping an election on May 9 and has been living up to his nickname, “the punisher”. Philippine police have been conducting night raids almost on a daily basis and revived a curfew for minors that had not been enforced for years, rounding up minors drinking on the streets. (Photo by Dondi Tawatao/Getty Images)

The Ivanpah Solar Electric Generating System is seen in an aerial view on February 20, 2014 in the Mojave Desert in California near Primm, Nevada. The largest solar thermal power-tower system in the world, owned by NRG Energy, Google and BrightSource Energy, opened last week in the Ivanpah Dry Lake and uses 347,000 computer-controlled mirrors to focus sunlight onto boilers on top of three 459-foot towers, where water is heated to produce steam to power turbines providing power to more than 140,000 California homes. (Photo by Ethan Miller/Getty Images)

A dejected German Grenadier carrying a machine gun on his shoulder in front of a building on fire during the German retreat in Russia. (Photo by Keystone/Getty Images). 1944