Both Brazil and Argentina began developing nuclear capabilities while under military rule. While Argentina has expanded its nuclear power generation capacity Brazil has gone into nuclear fuel processing and hopes to deploy the technology into a nuclear-powered submarine it plans to build with French help.
Agreements for the joint defense production program are in place but, as the implementation nears, questions are being asked about its nuclear component.
French President Nicolas Sarkozy spearheaded a marketing drive that secured France much needed cash in a deal that includes the supply and joint construction of four diesel-electric submarines and a fifth nuclear-powered submarine.
Officials say the French help in the so-called ProSub program covers only the non-nuclear components of the planned submersible.
Brazil has an advanced nuclear program dating to the 1950s that has drawn support at various stages from France, Germany and the United States. After helping Brazil set up research reactors, mainly in response to the Argentine nuclear program, U.S. officials began limiting Brazilian nuclear development under military rule.
However, Brazil now has both uranium resources and reprocessing facilities with a significant degree of autonomy. It wants to use locally enriched nuclear fuel to power the naval vessel when it's built.
The debate centers on what else Brazil can do with its enriched uranium.
In the 1970s and 1980s, Brazil under military rule secretly pursued a military program to develop an atomic bomb. The program was abandoned and led to an Argentine-Brazilian deal, brokered by the International Atomic Energy Agency, to keep nuclear activities peaceful.
Former President Lula Inacio Lula da Silva sent confusing signals in his comments on the nuclear program but later declared Brazil has no plans to develop nuclear weapons.
More recently, speculation over Brazil's plans resurfaced in reports by the University of Oxford Center for Brazilian Studies and German magazine Der Spiegel. Of the four BRIC nations -- Brazil, Russia, India and China -- Brazil is the only one without a nuclear-powered submarine or nuclear weapons.
Political commentators said Brazil may want a nuclear-powered submarine as part of its claim to pre-eminence in South America. That path includes lobbying for a permanent seat on the U.N. Security Council.
"Brasilia's military leaders were genuinely shocked by the ease with which Argentina was defeated in the Falklands War," Lucius Lomax said in a commentary carried by MercoPress.
"The lesson which the Brazilians apparently took away from the war was the importance of submarines," Lomax said, citing Britain's success in the 1982 naval conflict that led to Argentine defeat.
Brazilian analysts who disagree with the nuclear bomb thesis say a program that includes deployment of nuclear power in weapons wouldn't pass congressional approval or win public endorsement.