American actress and model Christina Hendricks attends NBC's New York Mid Season Press Junket at Four Seasons Hotel New York on January 24, 2019 in New York City. (Photo by Jamie McCarthy/Getty Images)

Chrissy Teigen and daughter Luna Stephens seen on the streets of Manhattan on June 24, 2019 in New York City. (Photo by James Devaney/GC Images)

Two animatronic velociraptors are on display during a technical rehearsal of “Walking with Dinosaurs The Live Experience” at the Indoor Stadium in Singapore, 29 August 2019. “Walking with Dinosaurs The Live Experience” is based on the BBC series of the same name and will run from 29 August to 08 September. (Photo by Wallace Woon/EPA/EFE/Rex Features/Shutterstock)

American singer-songwriter and actress Mandy Moore arrives at the Walt Disney Television Emmy Party on September 22, 2019 in Los Angeles, California. (Photo by Mario Anzuoni/Reuters)

Puerto Rican model Aleyda Ortiz attends the 20th annual Latin GRAMMY Awards at MGM Grand Garden Arena on November 14, 2019 in Las Vegas, Nevada. (Photo by Danny Moloshok/Reuters)

Indigenous Q'eqchi girls practice taekwondo with their teacher, Danny Coy, on a dirt court in the middle of the village in Tipulcan village, San Pedro Carcha, Guatemala, on 25 November 2019 (issued 27 November 2019). Tipulcan village girls learn taekwondo to combat sexist violence and harassment they have suffered in their community in northern Guatemala. (Photo by Esteban Biba/EPA/EFE)

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.