Brazil has puzzled nuclear experts for decades. The country is one of a handful of states that has mastered all steps of the nuclear fuel cycle. Despite their capabilities, Brazilian authorities have long claimed they do not want to develop nuclear weapons in efforts to calm nuclear observers concerned about proliferation risks. On June 6 of this year, the Brazilian government and the International Atomic Energy Agency (IAEA) started negotiations to allow the country to use nuclear fuel in its slow-burning submarine program. With this announcement, the administration of the Brazilian president Jair Bolsonaro is taking steps to fulfill a long-standing attempt to develop a Brazilian nuclear-powered submarine. Bolsonaro’s policy could bring Brazil to the verge of further expanding the country’s existing nuclear capabilities. Some observers fear that the security framework between the United States, the United Kingdom, and Australia (commonly known as AUKUS) might have opened the door for non-nuclear-weapon states, like Brazil, to negotiate with the IAEA over safeguards provisions for submarines. While the international context influenced Bolsonaro’s decision, the president proposed this action months before the presidential elections in October, where he will face former president Luiz Inácio Lula da Silva. This text explains Brazil’s nuclear capabilities, the long-standing attempts to develop a nuclear-powered submarine, and Bolsonaro’s current calculus. Overview of Brazil’s Nuclear Capabilities Brazil has been one of the leading suppliers of nuclear minerals since the dawn of the atomic age. Since the late 1940s, Brazilian authorities have invested in nuclear development to achieve energy autonomy instead of just being a supplier of nuclear minerals. Today, the country is one of a handful of states with the technology and knowledge to engage in all the steps of the nuclear fuel cycle. The Brazilian nuclear program includes uranium mining and milling, uranium conversion and enrichment, and nuclear energy production. Civilian and military authorities share responsibility for Brazilian nuclear capabilities. The state-owned Nuclear Industries of Brazil oversees commercial nuclear fuel cycle activities. The Navy is the sole owner of uranium enrichment technologies in the country. The Navy usually does not enrich to levels above 4.3% uranium-235 (U-235). When research reactors require 19.9% U-235, the Navy has to notify the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC), IAEA, and the Brazilian National Nuclear Energy Commission. Brazil’s Decades-Long Quest to Acquire a Nuclear-Powered Submarine Brazilian authorities have sought to develop naval nuclear propulsion since 1979. This goal has worried international nuclear observers for decades. However, Brazilian researchers argue that the country’s quest is part of a project aimed at modernizing the Brazilian economy and gaining international influence, not an effort to develop nuclear weapons. Some scholars explain that efforts to prevent Brazilian proliferation have been counterproductive. Brazilian authorities claim they do not want to acquire nuclear weapons. Thus, when nonproliferation policies target them, they commit to accelerating the acquisition of nuclear technologies. The administration of Fernando Henrique Cardoso brought Brazil into regional and international nonproliferation mechanisms by the 1990s. He fully complied with the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean in 1994 and signed the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in 1998. With these actions, the Brazilian president signaled the country’s commitment to nonproliferation norms. At the same time, Cardoso renewed deliberations on building a nuclear-powered submarine, which would use an indigenously built reactor. Cardoso’s last year in government was 2002. He left office without delivering on the promise to build a nuclear submarine. Plans stopped because Brazil faced financial instability and slow economic growth, not because the country abandoned this goal. Lula da Silva became the Brazilian president in 2003. International observers expressed some anxieties about the Brazilian nuclear intentions during his administration. Brazilian nuclear authorities denied IAEA inspectors access to the centrifuges located in the state of Rio de Janeiro in 2004. Lula argued that he was protecting Brazilian industrial secrets and that the IAEA inspections were unnecessary since ABACC inspectors already had access to this facility. These concerns increased in 2008 when the Brazilian National Defense Strategy stated that the country would not sign the NPT Additional Protocol, which grants the IAEA complementary inspection authority. Brazilian authorities explained that, unless NPT nuclear-weapon states disarmed, their country would not add more commitments to its existing safeguards agreement with the IAEA. By 2018, Togzhan Kassenova, Lucas Perez Florentino, and Matias Spektor wrote that the project of building a nuclear-powered submarine appeared to be irreversible. The Brazilian Navy has been working with the French company Naval Group to acquire the technology they need to build this submarine. The Navy is responsible for the nuclear components of the submarine, while Naval Group provides the hull design and other non-nuclear technologies. Hence, Bolsonaro’s step is just the latest development in a long-standing effort–not a departure from Brazil’s nuclear policies. Jair Bolsonaro’s Promise to Transform Brazil’s Nuclear Policy Jair Bolsonaro started his mandate as the president of Brazil in January 2019. He came into office with an ambitious nuclear agenda. His administration found the industrial infrastructure for constructing a nuclear-powered submarine already in place. The capability is currently used to build conventional submarines. During his first years as president, Bolsonaro began to open the nuclear sector to private investment, changed nuclear diplomacy, and restated the country’s long-standing goal of acquiring additional nuclear capabilities. In 2021, the Navy started building a Sao Paolo-based reactor prototype that a nuclear-powered submarine could use. Bolsonaro has rallied its base around the notion that former presidents accepted unfair limits on Brazilian nuclear capabilities. Article 21 of the Brazilian constitution prohibits using nuclear technology for non-peaceful purposes. The article states that “all nuclear activity within the national territory shall be allowed for peaceful purposes and shall be subject to approval by the National Congress.” Bolsonaro has criticized this commitment as too constraining. Moreover, Bolsonaro’s base has called for constructing a Brazilian nuclear weapon in a petition on the Brazilian Senate’s website. Hence, Bolsonaro might capitalize on the opening of the negotiations between Brazil and the IAEA to mobilize his base as the presidential election in October approaches. He could argue that he is taking one more step toward expanding Brazil’s nuclear capabilities beyond and above what Lula da Silva did when he was president. The Brazilian president might also use the negotiations with the IAEA to mobilize his supporters in the armed forces. The Brazilian military argues that it needs a nuclear-powered submarine to protect the country’s coastline, where most of the country’s population lives and most of Brazil’s oil reserves reside. Thus, Bolsonaro would increase the Navy’s capabilities by fulfilling a long-standing promise. The submarine program could also lead to the construction of a functional nuclear submarine industry in Brazil. This development would open new markets for Brazil’s arms industry, which supported Bolsonaro during the presidential elections in 2018. The Bolsonaro administration will face four obstacles in its quest to build a nuclear-powered submarine. First, Brazil will need to accept more comprehensive safeguard measures allowing IAEA inspectors to scrutinize the country’s nuclear installations. Historically, however, Brazilian authorities have rejected NPT additional protocols arguing that these are tools nuclear-weapon states use to discriminate against non-nuclear powers. Second, Brazil will need to secure the fuel for the submarine. While the country has mastered the nuclear fuel cycle, it cannot produce this fuel on its own. Thus, Brazil will need to secure the cooperation of a nuclear-weapon state. Bolsonaro sought to open negotiations with Russia when he visited Moscow in February of this year, but the Russian invasion of Ukraine has halted these discussions. Third, expanding Brazil’s nuclear program will shift the balance between the nuclear program’s civilian and military branches. The Navy will potentially have more influence over the Brazilian nuclear enterprise, transforming the policy-making context in the country. While Bolsonaro might receive the support of the armed forces for this change, he might face resistance from civilian bureaucrats. Forth, political corruption in the nuclear field might slow down Bolsonaro’s plans. Experts on the Brazilian nuclear enterprise have documented various corruption scandals. The pattern among these cases seems to be that politicians nominate managers that use their positions to attract funds from private companies seeking to secure government contracts. Opportunities Amidst Nuclear Proliferation Dangers The negotiations between the Brazilian government and the IAEA to use nuclear fuel for a nuclear-powered submarine have made nuclear observers worried about proliferation dangers. While the risks are real, these talks could open an opportunity to improve the effectiveness of the regulatory processes that govern Brazil’s nuclear sector. Domestically, constructing a nuclear-powered submarine would trigger a debate around the “peaceful uses” of military nuclear technology in a non-nuclear-weapon state, especially one that limits nuclear applications in its constitution. Internationally, while Brazil has rejected the NPT Additional Protocol, the international community could use the negotiations between Brazil and the IAEA to design innovative safeguards agreements. Thus, even if the Bolsonaro administration took this step for domestic reasons, it could have significant international consequences for the global nuclear order. J. Luis Rodriguez (@luisrodaquino) is a Stanton Nuclear Security Postdoctoral Fellow in the Center for International Security and Cooperation (CISAC) at Stanford University. His research studies how the Global South builds and maintains limits on the use of force through international law and organization. He holds a Ph.D. from the Department of Political Science at Johns Hopkins University.