Russian President Vladimir Putin (R) shakes hands with Syrian President Bashar al-Assad during a meeting at the Kremlin in Moscow, Russia, October 20, 2015. Assad flew to Moscow on Tuesday evening to personally thank Putin for his military support, in a surprise visit that underlined how Russia has become a major player in the Middle East. Picture taken October 20, 2015. REUTERS/Alexei Druzhinin/RIA Novosti/Kremlin ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.