A family swims in Lake Nicaragua, which will encompass nearly half of the proposed canal's 172-mile route. Environmentalists worry that oil spills, pollution and dredging will destroy the country's largest supply of fresh water. Carrie Kahn/NPR hide caption

itoggle caption Carrie Kahn/NPR

President of Panama, Ricardo Martinelli (left), talks next to Spain's Minister of Public Works and Transport, Ana Pastor, during a news conference after a meeting at the Presidential Palace in Panama City, Panama, on Monday. Alejandro Bolivar/EPA/Landov hide caption

itoggle caption Alejandro Bolivar/EPA/Landov

Men sit by the side of the Panama Canal as a ship sails past in Gamboa near Panama City, last month. The expansion project is aimed at accommodating the world's largest container ships. Arnulfo Franco/AP hide caption

itoggle caption Arnulfo Franco/AP

Egyptian cleric Osama Mustafa Hasan Nasr, photographed in 2007. Better known as Abu Omar, he was allegedly kidnapped by CIA agents in Italy in 2003 and taken to Egypt for interrogation. Amr Nabil/Associated Press hide caption

itoggle caption Amr Nabil/Associated Press