In this aerial image, debris of the Japanese Imperial Navy fighter A6M “Zero” is seen in the field on August 29, 2016 in Babeldaob Island, Palau. The war was opened up 75 years ago by Imperial Japan against the allied forces, including the United States, by the Pearl Harbour attack on December 7, 1941, claimed more than 2 million lives until Japan's surrender in 1945. (Photo by The Asahi Shimbun via Getty Images)

Military enthusiasts take part in a re-enactment of the World War II battle of Stalingrad at the “Stalin Line” memorial, near the village of Goroshki, Belarus, February 27, 2016. (Photo by Vasily Fedosenko/Reuters)

A man yells for help minutes after a Serb shell hit a crowded pedestrian walkway in Sarajevo, May 1993. Radovan Karadzic, a 70-year-old former psychiatrist, still in robust health, is the most senior political figure to be convicted by the International Criminal Tribunal for the Former Yugoslavia. He was found guilty of 10 out of 11 charges. He was acquitted of a second count of genocide in Bosnian towns. (Photo by Reuters)

The body of one of several U.S. soldiers who were executed after being captured by North Korean troops just south of Seoul in early July 1950. (Photo by AP Photo)

X Factor and Celebrity Big Brother starlet Chloe Khan is seen working up a sweat at her luxury home on August 30, 2016. The CBB star squeezed into a pair of super-tight leggings and a teeny crop top for a very public workout. She may be a self-made millionaire, but life wasn't always so good for Chloe Khan. The Celebrity Big Brother star, 25, has revealed she was brought up in poverty as a child in Wakefield, West Yorkshire, UK. Chloe lived with her mother on a council estate before she auditioned for the X Factor and became a playboy model. (Photo by Palace Lee)

A picture made available on 08 February 2017 shows staff playing with cats inside the Super Very Very Important Cat (VVIC) room at the CATZONIA cat hotel in Damansara, outside Kuala Lumpur, Malaysia, 07 February 2017. (Photo by Fazry Ismail/EPA)

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.