Aeronautics and Space engineer at France's Compagnie Maritime d'Expertises, or Comex, Arnaud Prost (C) meets with a jogger as he tests on the ground the “Gandolfi 2” underwater training suit for spacewalk, on January 20, 2016 in the calanques region (rocky inlets) of Marseille. The underwater training suit “Gandolfi 2”, developed with the European Space Agency (ESA), is designed for training astronauts underwater to simulate space gravity for the astronaut's extravehicular activities (EVAs). (Photo by Boris Horvat/AFP Photo)

A view of one of the dioramas contained inside iron boxes as part of the “S.A.C.R.E.D” installation by Chinese artist Ai Weiwei during a media preview at the cathedral in Cuenca, Spain, July 21, 2016. Ai Weiwei has reproduced scenes of his incarceration for a new art installation, a series of almost life-size dioramas – encased in steel boxes – showing his life in jail. (Photo by Susana Vera/Reuters)

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 pro-Russian rebel shows his t-shirt depicting Russian President Vladimir Putin at a checkpoint in the village of Chornukhyne near the town of Debaltseve, north-east from Donetsk, March 12, 2015. (Photo by Marko Djurica/Reuters)

Goat herder Dana McGregor's goats Pismo, left, and Goatee surf at San Onofre State Beach, Calif, on July 11, 2012. McGregor started taking Pismo's mother Goatee to the beach, and it wasn't long before she was on a surfboard. When Pismo was born, McGregor put her on a board too, and she was a natural, he says. (Photo by Rod Veal/The Orange County Register via AP)

Indian Muslim children hold anti-US placards as they participate in a protest meeting against the film “Innocence of Muslims” in Kolkata on October 5, 2012. A low-budget, US-produced “Innocence of Muslims” movie has incited a wave of bloody anti-US violence in Libya, Egypt, Sudan, Tunisia, Yemen and in several other countries across the Muslim world. (Photo by Dibyangshu Sarkar/AFP/AFP Photo)

Chinese butchers catch a pig to slaughter on January 31, 2005 in Jinzhai County, Anhui Province, China. (Photo by Cancan Chu/GettyImages)

Caroline Wozniacki of Denmark serves in her match against Kaia Kanepi of Estonia during day four of the Toray Pan Pacific Open at Ariake Colosseum on September 28, 2011 in Tokyo, Japan. (Photo by Koji Watanabe/Getty Images)