Russian President Vladimir Putin (right) hosts Syrian President Bashar Assad during a meeting at the Kremlin in Moscow. The meeting took place in October, shortly after Russia began a bombing campaign in Syria in support of Assad. Putin abruptly announced Monday that Russia was withdrawing most of its military forces. Alexey Druzhinin/AFP/Getty Images hide caption

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Russia's Vladimir Putin makes a speech in 2009 after receiving an award in Dresden, Germany, where he served as a KGB officer during the Cold War. Norbert Millauer/AFP/Getty Images hide caption

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Spy Vs. Spies: Why Deciphering Putin Is So Hard For U.S. Intelligence
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Chechen leader Ramzan Kadyrov (poster in top left) is a staunch supporter of Russian President Vladimir Putin, but both men have been criticized by human rights groups. Tens of thousands of people took part in a state-sponsored rally in Chechnya's capital Grozny on Jan. 22, with many holding posters of Kadyrov, Putin (right) and Kadyrov's late father, Akhmad Kadyrov (center). Ilia Varlamov/AFP/Getty Images hide caption

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Chechnya's Strongman Praises Putin, Threatens 'Traitors'
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Alexander Litvinenko, a former Russian security agent, died in 2006 after drinking tea laced with the radioactive element polonium at a London hotel. A British inquiry found Thursday that his death was the work of the Russian security service. Natasja Weitsz/Getty Images hide caption

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Marina Litvinenko, whose husband died in 2006 after being poisoned, spoke to the media after a British court issued a report saying Alexander Litvinenko had been murdered. Ben Pruchnie/Getty Images hide caption

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"I trust her, she is a very open person," Vladimir Putin said of German Chancellor Angela Merkel, seen here at last month's climate talks in Paris. But, he told the German daily Bild, "she is also subject to certain constraints and limitations." Alain Jocard/AFP/Getty Images hide caption

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When Russia began its bombing campaign in Syria, Russian officials said it would be a short-term air operation. Since then, things have gotten messier. In his state of the nation speech Thursday, President Putin reminded Russians that it took nearly a decade to crush terrorists who staged attacks around Russia in the 1990s. He cast the fight in Syria in similar terms. Ivan Sekretarev/AP hide caption

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With Few Signs Of Progress, Russia's Putin Warns Of Long Fight In Syria
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Russian President Vladimir Putin arrives on day two of the G-20 Turkey Leaders Summit on November 16, 2015 in Antalya. Ozan Kose /AFP/Getty Images hide caption

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Deputy Secretary of State Tony Blinken Discusses Russia And Syria
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Egyptian military vehicles approach the wreckage of a Russian passenger jet bound for St. Petersburg, Russia, on Nov. 1 after it crashed in Egypt's Sinai peninsula. Maxim Grigoriev/AP hide caption

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Russian President Vladimir Putin shakes hands with Syrian President Bashar Assad during Tuesday's meeting at the Kremlin in Moscow. RIA Novosti/Reuters/Landov hide caption

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Syria's Assad Visits Moscow To Discuss Military Plans With Putin
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Russian President Vladimir Putin, right, shakes hands with Syrian President Bashar Assad in the Kremlin. Assad was in Moscow, in his first known trip abroad since the war broke out in Syria in 2011, to meet his strongest ally Russian leader Vladimir Putin. Alexei Druzhinin/AP hide caption

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The Russian leader, shown here as "Vladimir Vladimirovich Buddha," was depicted as various pop culture heroes and religious, mythical and historical figures at a Moscow exhibition on Wednesday, his 63rd birthday. MAXIM SHIPENKOV/EPA /LANDOV hide caption

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In Honor Of His 63rd, Putin Plays Hockey And Is Painted As The Buddha
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