Cars pass a tank position close to the Russian border near the Ukrainian city of Kharkiv March 24, 2014. U.S. President Barack Obama sought support from European allies and China on Monday to isolate Russia over its seizure of Crimea, and Ukraine told its remaining troops to leave the region after Russian forces overran one of Kiev's last bases there. (Photo by Dmitry Neymyrok/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)

A young protester takes part in a protest near Tahrir Square to call for the fall of Islamist President on January 24, 2012 in Cairo. (Photo by Mohammed Abed/AFP Photo via The Atlantic)

People in historical uniforms prepare for a parade at Red Square commemorating the 75th anniversary of the Red Army’s defence of Moscow during the second world war in Moscow, Russia on November 7, 2016. (Photo by Stanislav Krasilnikov/TASS)

A Ukrainian man stands in protest in front of gunmen in unmarked uniforms as they stand guard in Balaklava, on the outskirts of Sevastopol, Ukraine, Saturday, March 1, 2014. (Photo by Andrew Lubimov/AP Photo)

A Russian air force technician reports to a pilot that a bomber is ready for a combat mission at Hemeimeem air base in Syria Wednesday January 20, 2016. Russian warplanes have flown over 5,700 combat missions since Moscow launched its air campaign in Syria on September 30, 2015. (Photo by Vladimir Isachenkov/AP Photo)

Ivan Plakhuta, 54, the owner of a small workshop manufacturing valenki, Russian traditional footwear, rolls a valenok in the remote Siberian village of Bolshaya Rechka, located in Taiga area in the foothills of the Western Sayan Mountain Ridge in the Yermakovsky district of Krasnoyarsk region, Russia, November 10, 2015. (Photo by Ilya Naymushin/Reuters)

A 2S5 Giatsint self- propelled gun fires during tactical exercises held by artillery detachments of the Russian Eastern Military District' s 5th Army at the Sergeyevsky training ground in Primorye Territory, Russia on March 21, 2017. Over 2500 servicemen practice combat skills received in 2017 winter training exercises. (Photo by Yuri Smityuk/TASS)