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.

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

Joseph Szabo was a frustrated high-school teacher in need of inspiration – so he started photographing his students, and captured all the angst and excitement of being caught between childhood and adulthood. Here: “Priscilla”, 1969. (Photo by Joseph Szabo/Courtesy of Michael Hoppen Gallery/The Guardian)

A model wears a creation during the presentation of Chanel Cruise collection in Paris, Wednesday, May 3, 2017. Chanel is hosting its itinerant resort show, destined for glamorous women who sojourn on cruise ships. (Photo by Francois Mori/AP Photo)

Attendee Emily poses for a picture at 2017 Comic-Con International on July 20, 2017 in San Diego, California. (Photo by Mike Blake/Reuters)

A picture made available 27 November 2015 shows a handler putting his head between the gaping fangs of a crocodile during a show at the Samutprakarn Crocodile Farm and Zoo, Samutprakarn province, outside Bangkok, Thailand, 26 November 2015. The farm and zoo claims to be the world's largest crocodile farm with more than 80,000 freshwater and marine crocodiles, and offers shows such as crocodile wrestling to attract tourists. (Photo by Diego Azubel/EPA)

Pope Francis waves as he arrives at the Kangemi slums on the outskirts of Kenya's capital Nairobi, November 27, 2015. (Photo by Goran Tomasevic/Reuters)