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.

A man wears a protective face mask as he walks along the main market in downtown after the government eased the restrictions on movement aimed at containing the spread of the coronavirus disease (COVID-19), in Amman, Jordan on April 29, 2020. (Photo by Muhammad Hamed/Reuters)

This picture taken on May 4, 2020 shows gentoo penguins chasing krill during feeding time in their enclosure at the Ocean Park theme park, which is currently closed due to the COVID-19 novel coronavirus, in Hong Kong. Save for an absence of gawping crowds, life for the penguins of Hong Kong's Ocean Park has been much the same during the coronavirus pandemic – but their carers have worked long shifts to keep the monochrome troupe healthy. (Photo by Anthony Wallace/AFP Photo)

This image released by Paramount Pictures shows American singer Andra Day in “The United States vs Billie Holiday”. Day accepted the award best actress in a motion picture drama at the Golden Globe Awards on Sunday, February 28, 2021. (Photo by Takashi Seida/Paramount Pictures via AP Photo)

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)

Models prepare backstage ahead of the “Romance Was Born” show during Afterpay Fashion Week Australia Resort 22 Collections at Carriageworks on May 31, 2021 in Sydney, Australia. (Photo by Jessica Hromas/The Guardian)

US actress Tiffany Haddish attends a photocall for the film “The Card Counter” presented in competition during the 78th Venice Film Festival, on September 2, 2021 at Venice Lido. (Photo by Yara Nardi/Reuters)