Runners gather at the start line for the annual “Santa Speedo Run”, a charity race through the streets of the Back Bay neighborhood of Boston. (Photo by Gretchen Ertl/Reuters)

Women wearing face-kini masks lie on a beach to rest in Qingdao, Shandong province, China, June 3, 2015. A pale complexion is highly prized as delicate and feminine in China while dark skin suggests tanning caused by farming the fields or other lowly, outdoor work. (Photo by Reuters/Stringer)

A sculptural artwork depicting former Chilean dictator Augusto Pinochet and headless presidents shot by a hooded high school student (not pictured) is seen at the Contemporary Art Museum in Santiago, December 2, 2014. The artwork, part of the “El ladrillo angular” (The angular brick) exhibition, portrays a student fighting against the ongoing continuity of dictatorship because of a political and economic system which has been impossible to destroy, according to “Papas Fritas” the artwork's creator. (Photo by Ivan Alvarado/Reuters)

An enterprising Chinese man pulls a bicycle cart packed high with bags of recyclable plastic containers in Shanghai July 25, 2002. The man sells each kilogram (2.2 pounds) of plastic for 0.08 yuan ($.01) to a nearby depot. (Photo by Claro Cortes IV/Reuters)

Lawmakers from the main opposition Republican People's Party (CHP) and ruling AK Party (R) scuffle during a debate on a legislation to boost police powers, at the Turkish Parliament in Ankara, Turkey, February 19, 2015. (Photo by Reuters/Stringer)

Scandinavia, always ahead of the bike infrastructure curve, has something else to share: a self-service cycle lift for hilly roads.

Marry Ousmane, 18, poses outside while wearing her prom dress on May 29, 2020 in the Brooklyn borough in New York City. Marry Ousmane is best friends with Patrice Toussaint and both are seniors at Edward Murrow high school in Brooklyn whose senior prom was canceled due to all schools being closed during the coronavirus pandemic. Toussaint said, “I've been planning for four years. I was going to have a send off party with a barbecue and a red carpet. I was going to have two dresses and wear a crown”. (Photo by Stephanie Keith/Getty Images)

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.