American model and actress Emily O'Hara Ratajkowski attends the Jacquemus Spring Summer 2020 show on June 24, 2019 in Valensole, France. (Photo by Arnold Jerocki/Getty Images)

Brazilian model Adriana Lima continues her vacation in Marbella, Spain on July 29, 2019. Dressed in a short blue jumpsuit. (Photo by The Mega Agency)

Belle Hassan is seen attending Lipstick and Champagne – party at STK on August 29, 2019 in London, England. (Photo by Jamie Lorriman/The Sun)

British actress Jameela Jamil arrives at the 2019 InStyle Awards at The Getty Center on October 21, 2019 in Los Angeles, California. (Photo by Steve Granitz/WireImage)

The selfie is the most popular photography trend of the internet today. It's gotten so popular, in fact, that even our beloved feline friends have started to catch on. I dare you to keep the smile off your face for this one!

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.

Photographers take photographs of the Large Air Tanker (LAT) C-130 Hercules, also known as “Thor”, as it drops a load of around 15,000 litres during a display by the Rural Fire Service ahead of the bushfire season at RAAF Base Richmond Sydney, Australia, September 1, 2017. (Photo by David Gray/Reuters)

Kendall Jenner (L) and Hailey Baldwin attend Harper's BAZAAR Celebration of “ICONS By Carine Roitfeld” at The Plaza Hotel presented by Infor, Laura Mercier, Stella Artois, FUJIFILM and SWAROVSKI on September 8, 2017 in New York City. (Photo by Bennett Raglin/Getty Images for Harper's BAZAAR)