Russian Mi-28N from the Berkuty (Golden Eagles) helicopter display team fly in formation during the “Aviadarts” military aviation competition at the Dubrovichi range near Ryazan, Russia, August 2, 2015. The aircraft started dipping down due to back propeller failure and crashed, killing one of two pilots, according to a Reuters photographer and official representatives of the competition. The aviation contest is part of the International Army Games, which are held in Russia from the 1st till the 15th of August with participants from 17 countries, according to organizers. (Photo by Maxim Shemetov/Reuters)

A girl has her helmet adjusted on the top of a tank during the Children's Day celebration at a military facility in Bangkok, Thailand January 9, 2016. Army barracks opened their doors to children to interact with their weapons and vehicles as part of the celebration. (Photo by Jorge Silva/Reuters)

A Palestinian student jumps through a fire ring during a military-style show at a school in Rafah in the southern Gaza Strip March 28, 2016. (Photo by Ibraheem Abu Mustafa/Reuters)

A female honor guard has lipstick applied as they prepare for an official welcoming ceremony outside the Great Hall of the People in Beijing, China on June 11, 2014. (Photo by Jason Lee/Reuters)

BAZ-69092-012 special wheeled chassis. Exhibition of military vehicles at Bronnitsy test range (a town in Moscow Oblast, Russia, located 54.5 kilometers (33.9 mi) southeast of central Moscow). Juny 10, 2011. (Photo by Vitaly Kuzmin)

Russian army soldiers, dressed in WWII era uniforms, march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

A participant in costume poses to a camera after a Halloween parade in Kawasaki, south of Tokyo, Japan October 30, 2016. More than 130,000 spectators turned up to watch the parade, where about 2,600 participants dressed up in costumes, according to the organiser. ((Photo by Kim Kyung-Hoon/Reuters)