Battle-weary American troops withdraw from Yong San in Korea. (Photo by Keystone/Getty Images). 1950

American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)

Residents of the Korean port of Inchon surrender to American troops. (Photo by Bert Hardy/Getty Images). 1950

The body of one of several U.S. soldiers who were executed after being captured by North Korean troops just south of Seoul in early July 1950. (Photo by AP Photo)

“The Spanish Civil War (The Crusade among Nationalists, Fourth Carlist War among Carlists, The Rebellion or Uprising among Republicans) was a major conflict fought in Spain from 17 July 1936 to 1 April 1939. An estimated total of 500,000 people lost their lives as a consequence of the War”. – Wikipedia

Photo: Women were among the Republican combatants during the Spanish Civil War. (Photo by Fox Photos/Getty Images). 1936

A Republican farmer defending a farm on the outskirts of Irun against Nationalist forces during the Spanish Civil War, 6th September 1936. A comrade lies dead by his side. (Photo by Keystone/Hulton Archive/Getty Images)

Star Wars collector James Burns, 44, poses for a photograph with some of his collection in London December 2, 2015. He said “I've met so many wonderful people, all over the world. It's a wonderful community of likeminded people with an interest in Star Wars. There's nothing else like it”. (Photo by Paul Hackett/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.