The theory centers on an ill-reputed jungle area known as the Triple Border, where Argentina, Brazil, and Paraguay meet.
The area is home to thousands of Muslim merchants who immigrated to South America from Syria and is known as a hotbed of smuggling, drug dealing, and arms sales.
U.S. officials have repeatedly said that merchants in the area launder money from illegal activities to Middle East terrorist groups, including Hezbollah. (Photo gallery: inside Hezbollah.)
At an August 24, 2004, press briefing in Washington, D.C., for example, the U.S. Treasury Department's Assistant Secretary for Terrorist Financing, Juan Zarate, referred to a "Hezbollah financier" imprisoned in Paraguay who Zarate said had been operating in the Triple Border.
"He was engaged in a panoply of different financial activities used to support Hezbollah, everything from extortion to counterfeiting of currency to smuggling," Zarate said. "Really, it was a potpourri of financial criminal activity that he was using and his counterparts were using to support Hezbollah and to send funds back to Lebanon." (Read the full transcript of the press briefing.)
But critics say the State Department's claims are little more than pretext for a subtle invasion.
"They have no evidence but claim a terrorist presence in the area so they can install a military base and exert control over the water," said Elsa Bruzzone, a policy specialist for the Buenos Aires-based CEMIDA, a pro-democracy group founded by retired Argentine military personnel.
Bruzzone also worries that loan conditions from foreign lenders will force national governments to privatize the aquifer to pay back funds.
She and other activists have pressured Mercosura regional trade bloc made up of the four countries that the aquifer underlies, plus Venezualato fight any foreign control over the aquifer.
Mercosur has recently proclaimed the aquifer to be the property of those national governments and initiated a committee to study the issue, Bruzzone says.
But many in South America feel the conspiracy theories are overblown, and U.S. officials have denied the allegations.
"The United States has no interest in the Guaraní Aquifer, which the U.S. government recognizes as an important resource for the inhabitants of the region," said a January statement released by the U.S. embassy in Paraguay.
Jorge Rucks is an Argentina-based official for the Organization of American States (OAS). The four Guaraní countries have elected the OAS to serve as executor of the aquifer-development project.
Rucks stresses that the four Guaraní countries have power over the aquifer project.
He adds that the money managed by the UN and World Bank comes without strings.
"We are talking about grants, no credits," he said. "The money does not have to be paid back, and it carries no conditions."
But the history of colonial domination on this resource-rich and largely untapped continent keeps suspicions alive.
Miguel Auge is a hydrology professor at the University of Buenos Aires and was one of the first academics to initiate studies of the aquifer. He says South American governments and lawmakers should be careful.
"We can't forget the invasions that Latin American countries have suffered throughout history, because it is happening again," he said.
"Governments here have handed the most important patrimony we havewater, soil, oil, gas, and mineralsto foreign groups from North America and Europe."
The Guaraní Aquifer uproar recently affected a millionaire conservationist from the United States.
Douglas Tompkins, an ecologist and former owner of Esprit clothing line, owns large chunks of Chile and Argentina, some of which sit atop the aquifer.
Earlier this month Argentina's populist undersecretary of land and housing, Luis D'Elía, decided to cut chains and padlocks at Tompkins's ranch, allowing a group of Indian activists onto the property, located in the Esteros del Iberá wetlands in the north of Argentina.
D'Elía has told local media he is pushing legislation to seize Tompkins's land, in part because, D'Elía claims, the conservationist is part of the United States' effort to "grab control of our water."
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