Canadian-born Omar Khadr is seen in a courtroom sketch during a 2010 hearing at the U.S. military prison at Guantanamo Bay, Cuba. He was moved to a Canadian prison in 2012. Janet Hamlin/AP hide caption

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An airport official walks past a military aircraft destroyed by Saudi-led airstrikes, at the Sanaa International airport in Yemen on Tuesday. Destroyed runways prevent aid from being delivered. Hani Mohammed/AP hide caption

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Helicopter belonging to the Netherlands participates in NATO's Dynamic Mongoose anti-submarine exercise in the North Sea, off the coast of Norway, on May 4, 2015. MARIT HOMMEDAL/AFP/Getty Images hide caption

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Baltimore City State's Attorney Marilyn J. Mosby announces that criminal charges will be filed against Baltimore police officers in the death of Freddie Gray in Baltimore on Friday. Gray died in police custody after being arrested on April 12. Andrew Burton/Getty Images hide caption

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September 13, 2009 photo of Andreas Lubitz, who is believed to have deliberately crashed Germanwings Flight 9525 into a mountain in southern France on March 24, 2015, killing all 150 people on board. Getty Images/Getty Images hide caption

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Saudi King Salman (center) appears alongside then-Crown Prince Muqrin bin Abdulaziz (third from left) and then-deputy Crown Prince and Interior Minister Mohammed bin Nayef (left) in January. Muqrin has since been pushed aside to make way for Mohammed. Saul Loeb/AFP/Getty Images hide caption

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Japanese Prime Minister Shinzo Abe with U.S. Defense Secretary Ash Carter earlier this month in Tokyo. Abe's visit to the U.S. this week features an agreement for the Japanese military to have a more active role. Franck Robichon/AP hide caption

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The King Jacob, a Portuguese-flagged cargo vessel, was the first ship to arrive near the migrant boat that sank off the Libyan coast over the weekend. The boat had been carrying more than 800 people. Alessandro Fucarini/AP hide caption

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