Actress Kat Dennings arrives at the premiere of Paramount Pictures' and Marvel's “Thor” held at the El Capitan Theatre on May 2, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

A participant jumps during the Red Bull Jump and Freeze competition at the ski resort of Gudauri, Georgia, March 20, 2016. (Photo by David Mdzinarishvili/Reuters)

Model Kendall Jenner arrives on the red carpet for the annual White House Correspondents Association Dinner in Washington, U.S., April 30, 2016. (Photo by Jonathan Ernst/Reuters)

David Colturi of the USA dives from the 27 metre platform during the fifth stop of the Red Bull Cliff Diving World Series in Polignano a Mare, Italy on August 28 2016. (Photo by Dean Treml/ANSA/Red Bull Press Office)

Model Christine Teigen attends the 2014 Billboard Music Awards at the MGM Grand Garden Arena on May 18, 2014 in Las Vegas, Nevada. (Photo by Kevin Mazur/Billboard Awards 2014/WireImage)

The overall winner of the 2013 Red Bull Illume photography competition from Lorenz Holder. (Photo by Lorenz Holder/Red Bull)

A competitor jumps from the Old Bridge during Red Bull Cliff Diving Competition in Mostar, Bosnia and Herzegovina on August 15, 2015. (Photo by Dado Ruvic/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.