A hydroelectric plant in Ethiopia. The country hopes to harness the waters of the Blue Nile to export hydropower and to irrigate crops. Dawit Nida hide caption

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A hippopotamus wades into the waters of the Nile in Uganda. Miguel Juarez for NPR hide caption

toggle caption Miguel Juarez for NPR

U.S. Ambassador to the U.N. Susan Rice at a Security Council meeting in June. Emmanuel Dunand/AFP/Getty Images hide caption

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A new report says the biggest threat against the U.S. now comes in the form of homegrown terrorists. But in many ways, trying to catch homegrown terrorists is more complicated: The suspect could now be an MBA from Connecticut -- like Times Square attempted bomber Faisal Shahzad (above) -- or a college student from Minneapolis. AP/Orkut.com hide caption

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