A member of the mainly Christian “anti-balaka” (anti-machete) militia trains in the Boeing neighbourhood of Bangui, Central African Republic, on February 24, 2014. (Photo by Fred Dufour/AFP Photo)

Canada's Marissa Papaconstantinou makes her way to the finish line after falling in the Women's 200m T44 Final during day ten of the IPC World ParaAthletics Championships 2017 at London Stadium on July 23, 2017 in London, England. (Photo by Peter Cziborra/Reuters)

Star Wars enthusiasts wear costumes resembling what they say are three “Chew's Angels” during the 2015 Comic-Con International Convention in San Diego, California July 10, 2015. (Photo by Mario Anzuoni/Reuters)

Japan's Kana Muramoto and Chris Reed compete in the figure skating team event ice dance short dance during the Pyeongchang 2018 Winter Olympic Games at the Gangneung Ice Arena in Gangneung on February 11, 2018. (Photo by John Sibley/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 man crosses Canal Street in the wind and rain from Hurricane Isaac August 29, 2012. (Photo by David J. Phillip/Associated Press)

Cuban-American artist Jorge Rodriguez-Gerada's six-acre sand and soil “facescape” stretches across the JFK Hockey Field on the north side of the Reflecting Pool along the National Mall October 1, 2014 in Washington, DC. Titled “Out of Many, One” and composed of 2,500 tons of sand, 800 tons of top soil and eight miles of string, the piece is the artist's interpreative blending of 30 different men's faces. Rodriguez-Gereda used high-precision global positioning satellites to place 10,000 wood pegs as waypoints for the giant face. The piece will be open to the public beginning October 4 and will eventually be tilled back into the earth. (Photo by Chip Somodevilla/Getty Images)

A Syrian boy looks through a gate as others wait to cross into Syria at Oncupinar border crossing in the southeastern city of Kilis, Turkey February 11, 2016.. (Photo by Osman Orsal/Reuters)