President of Turkey Recep Tayyip Erdogan (2nd R) and Ukrainian President Petro Poroshenko (R) at Presidential Complex in Ankara, Turkey on March 9, 2016. (Ahmet Izgi/Anadolu Agency/Getty Images)
Russian President Vladimir Putin and Chinese President Xi Jinping during the Asia-Pacific Economic Cooperation (APEC) summit on November 9, 2014 in Beijing, China. (How Hwee Young - Pool/Getty Images)
Syrian opposition members inspect the site of a suspected chlorine gas attack by Assad regime forces in Jobar region of Damascus, Syria on November 13, 2014. (Lokman Sair/Anadolu Agency/Getty Images)
US Secretary of States John Kerry (R) beside of Russian Foreign Minister Sergei Lavrov (L) after the International Syria Support Group (ISSG) meeting in Munich on February 12, 2016. (CHRISTOF STACHE/AFP/Getty Images)
Russian President Vladimir Putin (R) speaks with US Secretary of State John Kerry during a meeting at the Kremlin in Moscow on December 15, 2015. (SERGEI KARPUKHIN/AFP/Getty Images)
Then-Turkish Prime Minister Recep Tayyip Erdogan (R) and Russia's president Vladimir Putin give a press conference in Istanbul on December 3, 2012. (BULENT KILIC/AFP/Getty Images)
US Vice President Joe Biden (L) gestures next to Turkish President Recep Tayyip Erdogan after a meeting at Yildiz Mabeyn Palace on January 23, 2016 in Istanbul. (SEDAT SUNA/AFP/Getty Images)
A Russian biker shows a banner depicting Joseph Stalin and reading a WWII slogan 'For the Motherland! For Stalin!' in Moscow on April 25, 2015. (DMITRY SEREBRYAKOV/AFP/Getty Images)