VORONEZH REGION, RUSSIA. MARCH 15, 2016. Pilots of Russian Air Force Sukhoi Su-34 fighter bombers, the first group of Russian military aircraft to return from Syria following an operation against the ISIL and other terrorist groups, line up during the arrival ceremony at a military installation in Voronezh Region. The Russian president has announced the withdrawal of the main part of Russia's military contingent from Syria, starting on March 15, 2016. Irina Sokolova/TASS (Photo by Irina Sokolova\TASS via Getty Images)
