Country Profiles: Argentina and Brazil

Argentina flagNPT: 1995 (Argentina) and 1998 (Brazil)
CTBT: 1998 (Argentina and Brazil)
First Test: none
First Hydrogen Bomb: none
Current number of nuclear weapons: 0

Brazil flagLast Updated: 2/27/02

Rivalry between Argentina and Brazil led the two South American nations to embark on nuclear weapons programs in the 1970s and 1980s. In the 1990s, however, they concluded a series of treaties that bound them to end their nuclear weapons development and to seek greater cooperation and transparency in their nuclear programs.

Brazil initiated a nuclear research program in the early 1930s, an endeavor aided by the concurrent discovery of vast domestic uranium ore deposits. Beginning in the 1940s, Brazil made several agreements with the United States to exchange mining rights for nuclear technology. West Germany and France also aided Brazil’s nuclear program. In 1975, Brazilian leaders decided to hasten their research and development program. They maintained a two-track program, with a public civilian nuclear research program and secret military nuclear weapons program operating separately, though likely with collaboration. An agreement with West Germany provided the growing program with a uranium enrichment facility, a plutonium reprocessing plant, other enrichment technology, and eight reactors for power generation. The United States opposed the program, but could only convince West Germany to enforce certain safeguards, which in the end it did not do. In 1987, these efforts led to successful enrichment of uranium (though not to weapons-grade level), and observers predicted that Brazil could have had nuclear weapons by 2000. To this day, Brazil has the most advanced nuclear facilities in Latin America, including a large ultracentrifuge enrichment plant, as well as a missile program.

Hot cells, which can be used to reprocess spent reactor fuel into plutonium for weapons, functioned secretly in Argentina from 1969 through 1972. However, Argentina’s nuclear weapons program dates to 1978, when Argentina was under military rule. Canada and West Germany provided power reactors, Switzerland provided a heavy water plant, and the Soviet Union supplied other equipment. The Argentine program succeeded in developing domestic technology for gaseous diffusion. It also achieved some plutonium production capabilities, but the plutonium separation pilot plant was never completed and was discontinued in 1990.

In spite of these covert programs, a certain degree of cooperation between Argentina and Brazil on nuclear issues existed from an early point: the military regimes that sponsored nuclear weapons programs also negotiated some transparency between the two countries’ civilian nuclear programs. In 1980, the Brazilian-Argentine Agreement on the Peaceful Use of Nuclear Energy attempted to establish technical cooperation and coordination of civilian nuclear policy. It was only with the arrival of democratically elected regimes in the 1980s, however, that significant progress toward cooperation began to be made. In 1985, Brazilian President Tancredo Neves and Argentine President Raul Alfonsin, both newly elected, agreed to further transparency and mutual inspections through the Joint Declaration on Nuclear Policy of Foz de Iguaçu. However, a more militaristic regime soon followed in Brazil, and few gains were made in the late 1980s.

By 1990, two ultranationalist presidents had come to power: Carlos Menem in Argentina and Fernando Collor de Mello in Brazil. Both were faced with a variety of pressures: severe economic hardship, large foreign debt, and the need to balance the power of the military with the power of civilian government. In response to these pressures, the two leaders sought cooperation, eventually concluding a series of agreements that defused the nuclear rivalry between the two countries and committed both to exclusively peaceful use of nuclear technology. These agreements took part in the context of a larger web of economic and political ties that emerged between South American nations during the 1990s. Collor de Mello formally exposed Brazil’s secret plan to build a nuclear weapon and made the symbolic gesture of shutting down a secret testing facility. (Of course, the gesture cast doubt on the effectiveness of the 1985 accord, since the facility had escaped detection under that agreement.) In November 1990, the two presidents signed the second Foz do Iguaçu declaration, which barred use of nuclear technology for military purposes and led to the creation, in 1991, of the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials. In 1994, Brazil ratified the Treaty of Tlatelolco, which created the Latin American Nuclear Weapons Free Zone, and in 1997 ratified the Nuclear Non-Proliferation Treaty. Argentina ratified the Treaty of Tlatelolco in 1994 and the NPT in 1995. Brazil and Argentina also agreed to allow IAEA safeguards over their nuclear installations, though they retained the rights over their technological secrets. In June 1998, Brazil joined seven other nations to form the New Agenda coalition, which called for the worldwide elimination of nuclear weapons.

Brazil and Argentina’s actions to reverse their nuclear programs are generally cited as a success story for nonproliferation. However, some doubts remain. Both nations, particularly Brazil, remain nuclear capable, and some analysts have questioned whether Brazil has entirely renounced its weapons program. For the time being, however, most indications are that the two countries are sincere in their efforts to prevent a nuclear arms race in South America. In fact, Brazil is part of the New Agenda group pushing the Nuclear Weapons States to uphold their NPT commitments to nuclear disarmament.


Goldman, Joe. “Argentina, Brazil Open to Inspections” Bulletin of the Atomic Scientists May 1991 47:4

Petrarolha, Fabios Lacerda Soares. “Rivals to march side by side” Bulletin of the Atomic Scientists September/October 1996 52:5