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.

Alexis Ren seen at Focus Features Los Angeles Special Screening of “Nocturnal Animals” at Hammer Museum on Friday, November 11, 2016, in Los Angeles. (Photo by Eric Charbonneau/Invision for Focus Features/AP Images)

Bebe Rexha attends the 61st Annual GRAMMY Awards at Staples Center on February 10, 2019 in Los Angeles, California. (Photo by Rich Fury/Getty Images for The Recording Academy)

American media personality Kim Kardashian seen on February 17, 2019 in Los Angeles, CA. (Photo by Hollywood To You/Star Max/GC Images)

Daniel Lismore arrives for the Brit Awards at the O2 Arena in London, Britain, February 20, 2019. (Photo by Peter Nicholls/Reuters)

A Palestinian woman reacts after inhaling tear gas fired by Israeli forces during a protest marking Land Day and the first anniversary of a surge of border protests, at the Israel-Gaza border fence, in the southern Gaza Strip on March 30, 2019. (Photo by Ashraf Abu Amrah/Reuters)

Two women react to the camera as Nightclub Circus hosts the first dance event, which will welcome 6,000 clubbers to the city's Bramley-Moore Dock warehouse on April 30, 2021 in Liverpool, England. The event is part of the national Events Research Programme which will provide data on how events could be permitted to safely reopen. (Photo by Anthony Devlin/Getty Images)