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.

Libyan rebel soldiers watch as they fire rockets (background) toward Libyan government troops near front-line positions April 6, 2011 outside of Brega, Libya. Rebel militias fighting against Libyan government loyalist soldiers continued their stand-off in the eastern Libyan desert today, regaining ground toward a key oil port while awaiting further NATO airstrikes in their quest to unseat longtime Libyan ruler Muammar Gaddafi. (Photo by Chris Hondros/Getty Images)

Melissa Sinclair livestock apprentice prepares seven year old Maisie the Highland cow ahead of the International Highland Cattle Show being held at Pollock Country Park on September 15, 2011 in Glasgow, Scotland. This year's event , takes place on Saturday 17th in the grounds of the park, with 30 breeders from across the UK attending with more than 100 head of cattle competing in 12 classes, to win the supreme champion. (Photo by Jeff J Mitchell/Getty Images)

Protest posters are attached to the walls surrounding the “Occupy London” camp outside St. Paul's Cathedral on November 01, 2011 in London, England. The Dean of St. Pauls Cathedral The Very Reverend Graeme Knowles resigned yesterday over the church's handling of the anti-capitalist “Occupy London” demonstration, which continues to occupy the grounds outside the cathedral. (Photo by Dan Kitwood/Getty Images)

Nikolay Skidan, a hunter, carries the skin of a wolf in the village of Khrapkovo, Belarus February 1, 2017. Wolf fur grows thickest in winter, so Belarussian hunter Vladimir Krivenchik only sets his traps once snow is on the ground. He and his wife live on the edge of the Chernobyl exclusion zone – 2,600 square km of land on the Belarus-Ukraine border that was contaminated by a nuclear disaster in 1986. (Photo by Vasily Fedosenko/Reuters)

A British photographer has captured the hilarious expressions pulled by dogs as they go for a run. From popping eyes to lolling tongues, Nick Ridley from Aylesbury in Buckinghamshire has managed to perfectly pause the pooches in time as they pull a host of funny faces in the great outdoors. The 56-year-old uses a fast shutter speed and lies on the ground snapping away as the dogs run towards him in order to get the perfect shot. Here: A Dogue de Bordeaux. (Photo by Nick Ridley Photography/Caters News Agency)

These beautiful images aim to show the more artistic side of Hawaii’s recent volcano eruption, highlighting the sheer power of Mother Nature and the act of creating new land. Photographer CJ Kale’s breathtaking works show the molten lava in its incredible vibrancy, whether it’s bursting from the ground in fireworks fashion or pouring into surrounding waters, causing steam to rise. (Photo by CJ Kale/Caters News Agency)

The winners of The London’s Natural History Museum's prestigious Wildlife Photographer of the Year for 2013 have finally been unveiled. Selected from almost 43,000 entries from 96 countries, the winners offer a glimpse of the stunning array of natural beauty on our planet. Photo: Canada: “Lucky pounce”. “Anticipating the pounce – that was the hardest part”, says Connor, who had come to Yellowstone National Park, Wyoming, USA, in search of wildlife as much as the spectacular landscape. He had found this fox, his first ever, on his last day in the park. It was so absorbed in hunting that Connor had plenty of time to get out of the car and settle behind a rock. It quartered the grassland, back and forth, and then started staring intently at a patch of ground, giving Connor just enough warning of the action to come. When it sprung up, Connor got his shot. And when it landed, the fox got his mouse. (Photo by Connor Stefanison/Wildlife Photographer of the Year 2013)