Brazil rare earth deal proves militaries’ long-held interest in minerals

In 1939, the term “critical minerals” entered the legislative lexicon of the US when the country passed its Strategic and Critical Materials Stock Piling Act. They became defined as materials needed to supply military and industrial needs during a national emergency.

As that definition expanded through the 1970s and 1980s and into the 21st century, the origin story was gradually forgotten. Discussions on critical minerals today revolve around the energy transition: wind turbines, electric cars, batteries. However, a recent rare earth minerals deal serves as a reminder that this backstory remains – and may even be becoming more prominent.

In late August, the US Department of War announced a USD 750 million investment to secure supplies from the Serra Verde rare earths mine in Goiás, central-west Brazil.

Serra Verde produces dysprosium, terbium, neodymium and praseodymium, four of the 17 elements known as the rare earth minerals. Roughly half of global rare earth supplies are used to make permanent magnets. These magnets are used in wind turbines and electric vehicles, but also fighter jets, missiles and drones.

The interests of the global energy transition have become uncomfortably entwined with those of the military industrial complex. With the world increasingly insecure and ongoing tensions informing US-China trade relations, that has become all too difficult to ignore.

“Critical minerals were born in wartime,” says Phil Johnstone, a visiting fellow at the University of Sussex in the UK. “[Sustainability goals grew] in a time where it was basically accepted that the world was aiming for peace. The world’s changed and that is not the case anymore. Extraordinary things are happening that we couldn’t have imagined a few years ago.”

Brazil’s rare earths

Commercial production began at Serra Verde’s Pela Ema deposit in 2024, with a view to producing 6,400 tonnes of rare earth oxides a year by the end of 2027. The company claims to be the first “scale” producer of the four main rare earths outside Asia.

The US Department of War announced its investment as part of a wider USD 1.55 billion initiative spearheaded by its “economic defense unit”, saying: “This strategic partnership will establish a secure supply chain for rare earth elements critical for national defense and economic security.”

This interest reflects the security concerns that are increasingly shaping US foreign policy in Latin America and beyond. Over the past two decades, China has built a dominant position in critical minerals processing, representing 91% of the global production of refined rare earth output, and 94% of sintered permanent magnets (crucial components in the motors commonly used in, for example, wind turbines and defence systems).

The dominance of its main geopolitical and economic rival over the supply chain creates a strategic vulnerability for Washington, which relies on Chinese-made magnets and other technologies for its military hardware.

For Latin American countries, this renewed interest from the US in natural resources creates a dilemma: the White House under President Trump has shown itself willing to intervene directly in the region, as seen in Venezuela; on the other hand, China remains a key trading partner for most of the region. Careful balancing acts have become necessary.

The Trump administration has also put particular pressure on states where it deems Chinese investment could represent a “dual use” – the second use being the military. This was a key concern in Panama, where a court ruled that port management contracts held by a company in Hong Kong were unconstitutional: the US Secretary of State claimed China could use the Panama canal as a “choke point” in the event of a conflict.

Juan Enrique Serrano, a professor specialising in Latin America-China relations at the University of Chile, warns of the chilling effect these dynamics could have on domestic policy across Latin America: “There’s an unlikely but possible scenario in which the US argues that exports of lithium from Chile to China have a dual military use, because one gram ends up in some high-end computer on a plane.” Chile is South America’s leading lithium producer.

Environmental soldiers

For environmentalists, the increasing military interest in materials associated with the energy transition raises thorny questions.

The importance of these minerals to the energy transition has led many environmentalists to see mining as a necessary evil. While organisations like Greenpeace argue demand should be reduced to limit environmental harm, they accept that some mining will be necessary.

Serra Verde says it does not use intensive mining techniques, so its operations have a “much lower impact and superior sustainability credentials”. But mining is inherently extractive, with all of the impacts on the environment and local communities that follow.

Military interest in those materials makes moderate support for extraction harder to swallow. As Global Witness puts it: “This emerging military minerals complex is the opposite of a climate solution. Rather, it will accelerate our slide towards climate catastrophe.”

Military use of critical minerals could also divert materials away from the transition. Research has suggested the 7,500 tonnes of cobalt and 50,000 tonnes of graphite the US government plans to stockpile could instead produce 100,000 electric buses.

US troops fly over the Caribbean Sea, September 2025. Under President Trump, the US has been willing not only to intervene by force in Latin America, but also to secure the raw materials required for its military strategy (Image: Benjamin Applebaum / Chairman of the Joint Chiefs of Staff, CC BY)

Meanwhile, the International Institute for Environment and Development warns demand projections based on the energy transition alone are increasingly underestimating the true demand for critical minerals. This means more stress on mining areas than is currently anticipated.

Johnstone says environmental campaigners need to rekindle old alliances in this debate: “The peace movements and the green movements began as a shared thing in the 1960s and 70s [then] they drifted apart. It seems essential that those kind of coalitions come together again.”

Towards better regulation?

Johnstone believes existing sustainability frameworks are not well equipped for the current moment: “They’re all predicated on this kind of old world where sustainability is the main shared goal. They’re not really built for this world of geopolitical competition.”

Successfully protecting the energy transition from the interests of the military industrial complex will require strong regulations and global cooperation. Both were key demands in an open letter to UN delegates in July, signed by more than 100 advocacy organisations.

Monica de Bolle, a senior fellow at the nonprofit Peterson Institute for International Economics in the US, says: “Great demand exists [for rare earths], but how do we prioritise it? [We need] strong regulations, strong legal frameworks and some sort of institutional markers to be able to guide these decisions, because otherwise it’s a no man’s land.”

Latin American countries will also be wary of entering another round of extractivism in which their natural resources are extracted to the ultimate benefit of the Global North.

In September, Brazil signed a new critical minerals strategy into law focused on expanding domestic manufacturing and processing. It created the National Council for the Industrialisation of Critical and Strategic Minerals (CIMCE).

Luciano de Almeida Freitas, a legal consultant at the US law firm Carlton Fields, writes that the law opens the way for Brazil to screen foreign investments, such as for Serra Verde. But he also notes the country is behind its partners in developing processing capacity: “Mining is only the first step.” Whether Brazil remains an “extraction site”, or can hold its own downstream will determine the “difference between resource sovereignty and industrial sovereignty”.

The world has changed greatly since 1939, with climate action and new technologies like AI joining the military as drivers of industrial demand. When it comes to critical minerals, however, some are finding that little has changed.