Members of the Iraqi Army fire towards Islamic State militant positions at the south of Mosul, Iraq December 10, 2016. (Photo by Alaa Al-Marjani/Reuters)

An army dog stands up as retiring soldiers salute their guard post before retirement in Suqian, Jiangsu province, China on November 29, 2017. (Photo by Reuters/China Stringer Network)

A military enthusiast dressed as World War Two Red Army officer sits in a cafe as he marks the 75th anniversary of the Nazi Germany invasion, in Brest, Belarus June 21, 2016. (Photo by Vasily Fedosenko/Reuters)

A young Free Syrian Army fighter holds a rifle in Haresta neighbourhood of Damascus January 16, 2013. (Photo by Goran Tomasevic/Reuters)

A South Sudanese People Liberation Army (SPLA) soldier patrols the streets in Malakal on January 21, 2014. (Photo by Harrison Ngethi/AFP Photo)

Then U.S. Army First Lieutenant Kirsten Griest (C) and fellow soldiers participate in combatives training during the Ranger Course on Fort Benning, Georgia, in this handout photograph taken on April 20, 2015 and obtained on August 20, 2015. When Griest and another woman completed the daunting U.S. Army Ranger school this week they helped end questions about whether women can serve as combat leaders, as the Pentagon is poised to open new roles, including elite Navy SEALs, to women in coming months. The feat by Griest and First Lieutenant Shaye Haver followed a re-evaluation of the role of women after their frontline involvement in Iraq and Afghanistan and the end of a rule barring them from combat roles in 2013. (Photo by Spc. Nikayla Shodeen/Reuters/U.S. Army)

Ukrainian state emblem is seen on a gun's holster as soldiers guard naval base in the village of Novoozernoye, some 91 km west of Crimean capital Simferopol, Ukraine, on Monday, March 3, 2014. Ukraine says Russian forces controlling the strategic region of Crimea are demanding that the crew of two Ukrainian warships in Sevastopol's harbor must surrender. (Photo by Ivan Sekretarev/AP Photo)

Relatives of the Afghan Army soldiers, who are trapped in Obde district of Herat while fighting against Taliban militants, protest to demand the government evacuate the injured soldiers, in Herat, Afghanistan, 17 June 2021. Afghan authorities said they are in the process to arrange the evacuation of Army soldiers from the restive district soon. There has been a particularly bloody spike in violence in the country in recent weeks, following the start of the withdrawal of US troops from the country, a process due to be complete by September 11. (Photo by Jalil Rezayee/EPA/EFE)