Revelers celebrate during fireworks marking the start of the New Year on Copacabana beach on January 1, 2017 in Rio de Janeiro, Brazil. Brazilian revelers traditionally dress in white to honor the New Year's holiday along with the Brazilian Goddess of the Sea- Iemanja. (Photo by Mario Tama/Getty Images)

The British Breitling Wingwalkers, Danielle Hughes and Emily Guilding, soar above the Palm Jumeirah in Dubai at 1,500 feet (460 meters) in excess of 100mp/h, ahead of their Dubai debut performance at the 2014 UIM Skydive Dubai XCAT World Powerboating Series, on Saturday, 13th December 2014. The British team is the only aerobatic formation display team who employ full time wingwalkers and fly their two Breitling-liveried 1930's Boeing Stearman bi-planes at Air Shows and major sporting events around the world. (Photo by Katsuhiko Tokunaga/Breitling via AP Images)

Supporters celebrate as they watch official results from the Union Election Commission on an LED screen in front of the National League for Democracy Party (NLD) head office in Yangon, November 9, 2015. Myanmar's ruling party conceded defeat in the country's general election on Monday, as the opposition led by democracy figurehead Aung San Suu Kyi appeared on course for a landslide victory that would ensure it can form the next government. "We lost," Union Solidarity and Development Party (USDP) acting chairman Htay Oo told Reuters in an interview a day after the Southeast Asian country's first free nationwide election in a quarter of a century. (Photo by Soe Zeya Tun/Reuters)

The original costumes for Star Wars character Darth Vader stand on display at “Star Wars: The Exhibition” at County hall on May 04, 2007 in London, England. (Photo by MJ Kim/Getty Images)

Chamrock, an Irish wolfhound, sports a green coat as he waits for the start of the St. Patrick's Day parade on March 17, 2012 in Chicago, Illinois. Tens of thousands took advantage of record high temperatures and sunny weather to attend the city's annual St. Patrick's Day celebration. (Photo by Brian Kersey/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.

This photo provided by Joan Marcus on August 28, 2015 shows ballerina Misty Copeland in the musical “On the Town” at the Lyric Theatre in New York. Until September 6, 2015 Copeland will play Miss Turnstiles, a love interest for one of three sailors enjoying a few hours of shore leave in 1940s New York. (Photo by Joan Marcus via AP Photo)

A picture released by the North Korean Central News Agency (KCNA) shows Kim Jong-un convening an urgent operation meeting at 0:30 am on March 29, 2013 at an undisclosed location, in which he ordered strategic rocket forces to be on standby to strike US and South Korean targets at any time. (Photo by KCNA via EPA)