President Obama speaks beside Russian President Dmitry Medvedev after signing New START documents in 2010. Now five years old, that treaty has taken on renewed relevance in light of the framework nuclear deal between the U.S. and Iran. Joe Klamar/AFP/Getty Images hide caption

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A Russian Emergencies Ministry ship is seen through the window of a helicopter during a rescue operation after the Russian trawler Dalniy Vostok sank off the coast of Kamchatka, in the Sea of Okhotsk, on Thursday. Reuters /Landov hide caption

itoggle caption Reuters /Landov

Cars drive past the Kremlin along the Moscow River last December. Foreign automakers had been ramping up production in Russia, but the country's economic woes have caused car sales to drop sharply. Several foreign automakers have cut back production, and General Motors is pulling out of Russia. Alexander Zemlianichenko/AP hide caption

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Polina, 37, rests in a hospital bed in St. Petersburg, Russia, in 2011. She is severely malnourished and suffers from numerous diseases, including tuberculosis, hepatitis C and HIV. Misha Friedman hide caption

itoggle caption Misha Friedman

The view west from London's newest skyscraper looks over the River Thames and St. Paul's Cathedral. Russians have flocked to the English property and banking sectors as the economy crumbles back home. Peter Macdiarmid/Getty Images hide caption

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A Ukrainian serviceman walks in the village of Pisky in the region of Donetsk controlled by Ukrainian forces on Feb. 26. Oleksandr Ratushniak/AFP/Getty Images hide caption

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Russian President Vladimir Putin (left) greets Supreme Court Chairman Vyacheslav Lebedev. The Kremlin says Putin, who has been out of public view for more than a week, is perfectly healthy. Alexei Druzhinin/AP hide caption

itoggle caption Alexei Druzhinin/AP

Police escort the suspects in the killing of Boris Nemtsov into a court house in Moscow, Russia, on Sunday. A total of five people have been arrested over the weekend in connection with the killing of the fierce opponent of President Vladimir Putin. Ivan Sekretarev/AP hide caption

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A portrait of Kremlin critic Boris Nemtsov and flowers photographed on Friday at the site where he was killed on February 27, with St. Basil's Cathedral seen in the background. Maxim Shemetov/Reuters/Landov hide caption

itoggle caption Maxim Shemetov/Reuters/Landov

Russian opposition leader Boris Nemtsov, who was shot dead last Friday, was one of the most outspoken critics of President Vladimir Putin. No arrests have been made in his killing. Ivan Sekretarev/AP hide caption

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Workers stand next to a gas pipeline not far from the central Ukrainian city of Poltava in June 2014. Ukraine imports much of its gas from Russia, which is once again threatening to cut off supplies in a dispute over payments. Sergei Supinsky/AFP/Getty Images hide caption

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