U.S Army combat camera photographer Spc. Hilda Clayton took this photo July 2, 2013 that was released by the U.S. Army, that shows an Afghan soldier engulfed in flame as a mortar tube explodes during an Afghan National Army live-fire training exercise in Laghman Province, Afghanistan. The accident killed Clayton and four Afghan National Army soldiers. (Photo by Spc. Hilda Clayton/U.S. Army via AP Photo)

A general view of the ghost town of a former Soviet military radar station near Skrunda, Latvia, April 9, 2016. (Photo by Ints Kalnins/Reuters)

An Afghan boy jumps off the turret of a Soviet tank on a hilltop on the the outskirts of Kabul, Sunday, March, 4, 2018. (Photo by Rahmat Gul/AP Photo)

Former Soviet leader Mikhail Gorbachev attends the Gorby 80 Gala at the Royal Albert Hall on March 30, 2011 in London, England. The concert is to celebrate the 80th birthday of the former Soviet leader Mikhail Gorbachev.

Museum assistant and former Soviet soldier, Sheikh Abdullah looks at a display in the Manzar-e Jahad, or Jihad Museum, which depicts the Soviet invasion of 1979 and the Afghan resistance, in Herat, on February 15, 2014. Sheikh Abdullah, who was a Soviet intelligence officer by the name of Khakimov Bakhrodin, was captured after being injured in battle with the Mujahideen. Abdullah stayed with his captors, converted to Islam and was renamed Abdullah. He never returned to his former homeland and now works at the Jihad Museum. (Photo by Aref Karimi/AFP Photo via The Atlantic)

People take a selfie at the abandoned former Soviet R12 nuclear missile launch site in Zeltini, Latvia, July 22, 2016. Hidden in the forests of Aluksne, near Latvia's north-eastern border with Russia, the remains of a former Soviet nuclear missile base are a magnet for tourists now rather than a top-secret site manned by soldiers. (Photo by Ints Kalnins/Reuters)

Members of ASC Tornados, the motorcycle display team of the Indian army, lie in a row on the ground as another performs a stunt by jumping over them during the 225th anniversary celebrations of Army Service Corps in Bangalore, India, Tuesday, December 8, 2015. The Army Service Corps which was established in 1790 is an arm of the Indian Army which handles its logistic support function. (Photo by Aijaz Rahi/AP Photo)