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.

The number of soldiers on both sides of WWII that were killed or went missing is just staggering. Now, the mystery surrounding one RAF pilot and what happened to him and his plane has been solved after 70 years. RAF flight Sergeant Dennis Copping climbed into his Kittyhawk P-40 aircraft in June 1942 to fly the plane to another airbase for repairs. He was never seen or heard from again.

A polar bear plays with a pylon during celebrations marking its first birthday in an enclosure at Tierpark Hellabrunn zoo in Munich December 9, 2014. (Photo by Michaela Rehle/Reuters)

Gabriella Papadakis and Guillaume Cizeron of France perform during the ice dance skating event at the ISU Grand Prix of Figure Skating final in Barcelona December 13, 2014. (Photo by Albert Gea/Reuters)

U.S. soldiers from the 3rd Cavalry Regiment take part in an artillery exercise on forward operating base Gamberi in the Laghman province of Afghanistan December 24, 2014. (Photo by Lucas Jackson/Reuters)

People view Singpoli Group's inaugural Rose Parade float as it undergoes its finishing touches in Pasadena, California December 30, 2014. The 126th Rose Parade will take place on New Years Day in Pasadena. (Photo by Jonathan Alcorn/Reuters)

A craftsman works on making human anatomy mannequins on April 23, 2014 in Depok, West Java, Indonesia. The mannequins are made from fiberglass and will be used in schools, hospitals and laboratories. (Photo by Nurcholis Anhari Lubis/Getty Images)

Storm clouds gather over the scene outside the Jewish Community Center in Leawood, Kansas following a shooting, on April 13, 2014. (Photo by John Sleezer/Kansas City Star/MCT)