A Nepalese boy gets ready to perform a stick dance during a rally held to pay tribute to the victims of an earthquake, in Bhaktapur, Nepal, Wednesday, September 2, 2015. Two powerful earthquakes in April and May devastated the Himalayan nation killing more than 8,800 people. (Photo by Niranjan Shrestha/AP Photo)

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.

An aerial view shows the 11/19 pit and twin slag heaps at the former coal mine site in Loos-en-Gohelle, northern France, November 1, 2015. Loos-en-Gohelle, a town of 7000 inhabitants in the North of France, marked by the closure of coal mines in 1970, has demonstrated a successful transition from coal to a green economy. (Photo by Pascal Rossignol/Reuters)

Street vendors hold campaign posters for presidential candidate Patrice Talon ahead of the second round of Benin's presidential election on Sunday in Cotonou, Benin, March 18, 2016. (Photo by Charles Placide Tossou/Reuters)

Filipinos cross a swelling river in Las Pinas city, south of Manila, Philippines, 09 July 2015. According to the Philippines State weather forecast, heavy rainfall is expected in Metro Manila and nearby provinces due to an enhanced Southwest Monsoon and Tropical Storm Linfa, Typhoon Chan-hom and Typhoon Nangka which are lining up across the Pacific Ocean. (Photo by Francis R. Malasig/EPA)

A model is filmed backstage before the Jeremy Scott Fall/Winter 2015 collection presentation at New York Fashion Week February 18, 2015. (Photo by Andrew Kelly/Reuters)

This undated handout picture made available on February 3, 2016 and provided by Russia's punk band Рussy Riot shows Рussy Riot frontwoman Nadezhda Tolokonnikova performing in the band's new music video titled “Chaika” in Moscow. Russian punk band Рussy Riot, which became a symbol of resistance for a church performance slamming President Vladimir Putin, released a new protest song on February 3 mocking a senior official for alleged corruption. Titled “Chaika”, the satirical song and accompanying video take aim at prosecutor general Yury Chaika, whose two sons have been accused of using their father's position to accrue large fortunes. (Photo by Andrey Noskov/AFP Photo/Russian Punk Band Рussy Riot)

The original costumes for Star Wars character Darth Vader stand on display at “Star Wars: The Exhibition” at County hall on May 04, 2007 in London, England. (Photo by MJ Kim/Getty Images)