Dr. P.A. Smithe was sent by the American Red Cross as a doctor and surgeon to work at a hospital in Vienna. He sailed to Europe in December 1915 and returned home in August 1916, according to his daughter, who donated his images to the National World War I Museum. Photo: Turkish army, including cavalry, infantry and artillery. (Photo by Dr. P.A. Smithe/National World War I Museum, Kansas City, Mo.)

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 Russian trenchmortar crew run to take up a new firing position in the Stalingrad area during the Great Patriotic War. (Photo by Keystone/Getty Images). October 1942

A scene showing one of the first trench battles is prepared for the opening of the 3D Panorama exhibition “Memory talks. The road through war” in the former Sevcabel port in St. Petersburg, Russia, 16 September 2019. Various 3D dioramas – containing genuine wartime items such as aircraft, tanks and artillery in original size – allow visitors to walk through scenes from the beginning to the end of WWII without any museum barriers. The exhibition opens from 19 September 2019 to May 2020. (Photo by Anatoly Maltsev/EPA/EFE)

A young woman employee of North American Aviation Incorporated, working over the landing gear mechanism of a P-51 fighter plane, Inglewood, California, 1942. (Photo by Alfred T. Palmer/Buyenlarge/Getty Images)

German field telegraph operators at work in Warsaw. (Photo by Hulton Archive/Getty Images). 1st October 1914

Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

In this image released by World Press Photo, Thursday April 15, 2021, by Ami Vitale for CNN, titled Rescue of Giraffes from Flooding Island, which won the first prize in the Nature Singles category, shows A Rothschild's giraffe (Giraffa camelopardalis rothschildi) is transported to safety in a custom-built barge from a flooded Longicharo Island, Lake Baringo, in western Kenya, on Dec. 3, 2020. (Photo by Ami Vitale for CNN, World Press Photo via AP Photo)