Brazil joins the NPT

On 18 September 1998, Brazil formally acceded to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The act was the culmination of a reorientation of foreign and nuclear policy begun at the start of that decade, signalling to the world the definitive renunciation of the military option and Brazil's consolidation as a “peaceful power”.

By signing, the country abandoned decades of resistance to a treaty it had previously deemed discriminatory, seeking in exchange greater international credibility and access to advanced technologies.

Since the NPT was created in 1968, Brazil had refused to sign it, arguing that the treaty “froze” the global power structure by allowing five nations to keep nuclear weapons while barring everyone else from developing them.

The end of the Cold War and redemocratisation changed that landscape. After creating ABACC with Argentina (1991) and accepting IAEA safeguards (1994), Brazil's continued absence from the NPT became a “political paradox” that bred mistrust and hampered access to supercomputers and other sensitive technological inputs from developed countries.

1. 20 June 1997
   President Fernando Henrique Cardoso sent Congress Message No. 716 proposing accession, together with a statement of reasons signed even by the military ministers.
2. 1997–1998
   Parliamentary debate: the bill moved through Congress for a year. Nationalist sectors and retired officers criticised the measure, but the government argued that national security was already assured by the accords with Argentina and that isolation was harmful.
3. 2 July 1998
   The National Congress approved Legislative Decree No. 65/98, authorising accession.
4. 18 September 1998
   Brazil deposited its instrument of ratification, and the treaty entered into force for the country immediately.

Joining the NPT allowed Brazil to enter the global nuclear mainstream, no longer seen as a potential proliferator. That commitment underpinned the revitalisation of the Brazilian nuclear programme in the 2000s, with construction resuming at Angra 2 and Angra 3 and the development of industrial uranium enrichment plants, now under full international transparency.