Breath at sunset, captures a sea turtle at a dive site called Black Rock. Kāʻanapali, Hawaiʻi, August 2013. (Photo by Christopher Doherty/Smithsonian.com)

The Dynasphere, an electrically-driven wheel, invented by Mr. J. A. Purves of Taunton and his son. It had 2.5 horse power and once attained a speed of 25 mph. (Photo by Fox Photos/Getty Images). 1932

A man passes by an unfinished street art graffiti made in a stairway by French street artists Zag and Sia in Paris on March 1, 2016. The two artists drew inspiration from famous “Liberty Leading the People” (La Liberte guidant le peuple) painting by French Eugene Delacroix commemorating the July Revolution of 1830 and viewed as a symbol of the French Republic. (Photo by Joel Saget/AFP Photo)

A PETA (People for the Ethical Treatment of Animals) activist with her body painted promotes veganism in Bangkok April 21, 2016. (Photo by Jorge Silva/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.

Football Soccer, England vs Wales, EURO 2016, Group B, Stade Bollaert-Delelis, Lens, France on June 16, 2016. Soccer fan Laura Woods from England fixes her makeup near riot police near the Lens stadium before the England vs Wales game. (Photo by Wolfgang Rattay/Reuters)

“The Tonight Show” host Jimmy Fallon, center, exits the water during the Chicago Polar Plunge, Sunday, March 2, 2014, in Chicago. Fallon joined Chicago Mayor Rahm Emanuel in the event. (Photo by Andrew A. Nelles/AP Photo)

An Army Sikorsky VH-34s Choctaw helicopter once used to transport President Dwight D. Eisenhower sits in a field at the 309th Aerospace Maintenance and Regeneration Group boneyard Thursday, May 14, 2015 at Davis-Monthan Air Force Base in Tucson, Ariz. President Eisenhower became the first chief executive to be transported by helicopter. Presidents Eisenhower and John F. Kennedy were transported in VH-34 helicopters and VH-34's served as “Army One” from 1958 through 1963. (Photo by Matt York/AP Photo)