The report, prepared by the Sustainable Development Solutions Network (SDSN) and the Earth Institute at Columbia University, showed Syria, Afghanistan and eight sub-Saharan countries as the 10 least happy places on earth to live. The top 10 this year were Denmark, Switzerland, Iceland, Norway, Finland, Canada, Netherlands, New Zealand, Australia, and Sweden. Denmark was in third place last year, behind Switzerland and Iceland. The bottom 10 were Madagascar, Tanzania, Liberia, Guinea, Rwanda, Benin, Afghanistan, Togo, Syria and Burundi. The United States came in at 13, the United Kingdom at 23, France at 32, and Italy at 50. Here: #8. NEW ZEALAND: A woman dives from a platform into a giant air bed at a park in Palmerston North September 29, 2011. (Photo by Marcos Brindicci/Reuters)

English actress and model Elizabeth Hurley launches Harrods beach and children's wear at the Knightsbridge store in London, England on December 6, 2006. (Photo by Daniel Deme/WENN)

Monsoon thunderstorm in Sierra Vista, Arizona. 9 Sept, 2011. (Photo by Steven Maguire)

A CRH train is seen passing through Nanjing South Railway Station, which is part of the Beijing-Shanghai High-Speed Railway Line, on March 27, 2011 in Nanjing, Jiangsu Province of China. The High-Speed railway line is 1,318 kilometres long, running between Beijing and Shanghai. The line will open on June 10, 2011. (Photo by ChinaFotoPress/Getty Images)

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.

Garrett Gerloff (L) of the USA GRT Yamaha WorldSBK Junior Team and Sandro Cortese (R) of Germany on OUTDO Kawasaki TPR colide during a warm up session of the the World Superbike Championship on Phillip Island, Victoria, Australia, 01 March 2020. (Photo by Scott Barbour/EPA/EFE)

A person walks by an Ocean Rebellion activist taking part in a demonstration outside Department for Environment, Food and Rural Affairs (DEFRA) in London, Britain on September 15, 2021. (Photo by Hannah McKay/Reuters)