Russian honour guards march during the military parade at Red Square in Moscow on November 7, 2018. Russia marks the 77th anniversary of the 1941 historical parade, when Red Army soldiers marched past the Kremlin walls towards the front line to fight Nazi Germany troops during World War Two. (Photo by Mladen Antonov/AFP Photo)

An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

Army paratroopers carry the casket of Private Howard at the Wellington Cathedral on December 21, 2010 in Wellington, New Zealand. Private Howard was serving with the British army when was killed by friendly fire from a US Air Force plane in Helmand Province, Afghanistan earlier this month. Private Howard is the fifth NZ-born soldier to be killed in action in Afghanistan. (Photo by Marty Melville/Getty Images)

Russian servicemen stand next to a Russian Yars RS-24 intercontinental ballistic missile system before a rehearsal for the Victory Day parade, with the Moscow International Business Center also known as “Moskva-City” seen in the background, at a range in Moscow, Russia, May 5, 2016. (Photo by Maxim Shemetov/Reuters)

Members of the local Cossack community undergo military training at a boot camp set up by the Russkiye Vityazi (Russian Knights) military patriotic club in the village of Sengileyevskoye, south of Stavropol, March 22, 2015. A group of cossacks from the village of Kazanskaya, who are planning a professional career at the military intelligence service, has arrived at a camp for training under the leadership of professional instructors. (Photo by Eduard Korniyenko/Reuters)

Russian President Vladimir Putin, center, uses a binocular, as Defense Minister Sergei Shoigu, left, and chief of Russia's military's General Staff Valery Gerasimov, right, observe military exercises near the Baikal Lake on Wednesday, July 17, 2013. (Photo by Alexei Nikolsky/AP Photo/RIA Novosti/Presidential Press Service)

Tech. Sgt. Milo Hinson, 3rd Combat Camera Squadron, uses a flashlight while shooting a Berretta 9mm during the night-fire portion of Advance Weapons, Tactics and Techniques training in San Antonio. During night-fire training, airmen learn how to tactically illuminate targets with flashlights and practice using night vision goggles. (Photo by Staff Sgt. Jonathan Snyder/U.S. Air Force). 2011

South Korean teenagers participate in a warfare exercise as part of the Special Warfare Command's training course at a military base on August 4, 2011 in Seoul, South Korea. About 1,000 civilian volunteers including middle and high school students participated in the special force's four-day training programme to develop their spiritual and physical strength. (Photo by Chung Sung-Jun/Getty Images)