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 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)

Model Bella Hadid poses on the red carpet of Rihanna's new Savage X Fenty collection show for New York Fashion Week at the Barclays Center in the Brooklyn borough of New York, U.S., September 10, 2019. (Photo by Shannon Stapleton/Reuters)

University students wearing Guy Fawkes masks pose for a photoshoot of a graduation ceremony to support anti-government protests at the Hong Kong Polytechnic University, in Hong Kong, China on October 30, 2019. (Photo by Tyrone Siu/Reuters)

Brazilian model and television personality Alessandra Ambrosio attends Alessandra Ambrosio And Darren Dzienciol's Horror In The Hills on October 31, 2019 in Beverly Hills, California. (Photo by Rochelle Brodin/Getty Images)

Rumor, a German shepherd and winner of Best In Show at the 141st Westminster Kennel Club Dog Show, is fed steak at Sardi's in New York, U.S., February 15, 2017. (Photo by Shannon Stapleton/Reuters)