In a nutshell: Tomahawk missiles and other precision-guided weapons rely on magnets that can withstand extreme heat, a requirement that has left the US defense industry exposed as China tightens its control over the rare-earth metals needed to produce them. China supplies nearly all of the world's samarium, a material used primarily in military applications. Magnets made from samarium can tolerate temperatures high enough to melt lead without losing their magnetic properties, making them essential components in high-speed electric motors, missile nose-cone guidance systems, and advanced aircraft.
As Beijing's new licensing rules on samarium and related materials restrict exports of these heat-resistant magnets, America's ability to produce precision-guided munitions has come under pressure. That squeeze has prompted the Trump administration to rely on a short-term workaround built around a French samarium stockpile, while racing to secure new non-Chinese sources before the reserve is exhausted.
To keep production moving, a deal involving two European companies opened an alternative supply channel. The material came from samarium nitrate that had been sitting for decades at a factory in France owned by Solvay, a Belgian chemical company that was once among the world's largest producers of rare-earth oxides.
Although Solvay stopped separating rare earths in France roughly 20 years ago because the operation had become "uneconomical," a company spokeswoman told The New York Times that Solvay retained its stock of semi-finished material and still possessed the expertise and equipment needed to refine it into a usable form.
Solvay helped pioneer solvent-based processes for separating the 17 rare-earth elements, and those capabilities allowed the company to convert the old samarium nitrate into feedstock suitable for magnet production. Less Common Metals, a firm near Liverpool, England, operated an older furnace capable of processing the refined samarium into metal. Together, Solvay's separation facilities and Less Common Metals' furnace enabled the European partners to transform a decades-old cache into fresh samarium-cobalt alloy inputs for US suppliers.
Arnold Magnetic Technologies, a Rochester, New York – based manufacturer of samarium-cobalt magnets, had built up more than a year's worth of samarium before China announced export controls on April 4. As that buffer began to shrink, Arnold turned to Grant Smith, chairman of Less Common Metals, who had already identified a Solvay stockpile in France as a potential non-Chinese source. Smith then assembled a group of buyers – including Arnold and Permag, the owner of longtime US defense supplier Electron Energy Corporation – forming a de facto buyers' club to justify processing the entire cache.
Smith arranged for Solvay's samarium to be shipped to Britain, where Less Common Metals is converting it into metal that will later be melted into alloys. Customers will press those alloys into blocks, which US factories will cut into magnets. The finished magnets are then integrated into motor systems inside fin actuators, which adjust a missile's trajectory by moving its fins during flight.
Smith estimated that Solvay's stockpile would supply his American defense-industry customers for more than a year, describing it as a temporary bridge while longer-term sources are developed.
US officials have worried about dependence on China for rare earths for more than a decade and have made repeated attempts to rebuild a domestic supply chain. The National Defense Authorization Acts of 2023 and 2024 gradually tightened restrictions on the use of Chinese rare-earth materials in US weapons systems, requiring such components to be free of Chinese content by January 1, 2027.
Enforcement, however, has been uneven, largely because viable alternatives were not yet available. In 2023 and 2024, when magnets were supposed to be made from non-Chinese sources, Lockheed Martin disclosed to the Pentagon that F-35 Joint Strike Fighter jets still contained Chinese-made magnets. The revelation led the military to halt production for months before ultimately issuing a waiver. Around the same time, Raytheon's parent company, RTX, warned in a Securities and Exchange Commission filing that "emerging laws and increasing regulatory requirements aimed at global supply chains may impact our ability to access certain materials."
China's suspension of samarium exports has given Beijing additional leverage over the United States and its allies at a moment when trade and security tensions are already elevated. During trade talks in London, China used its control over rare-earth magnet supplies to gain negotiating leverage with the Trump administration and the European Union.
The problem is acute. Aisha Haynes, a former Defense Department official responsible for supply chain issues, warned that unless new sources of samarium or viable substitute materials are developed, American manufacturers will be unable to produce fighter jets or precision-guided missiles at current levels.
The Trump administration has provided MP Materials, which owns a rare-earth mine in California, with a $150 million loan to expand its processing facilities to handle samarium as part of a broader multibillion-dollar initiative. The administration has also extended an $80 million loan to ReElement Technologies, an Indiana-based company using a novel technology to process samarium. In addition, Ucore Rare Metals, a Canadian firm, has received $22.4 million in grant funding from the US military to build a facility in Louisiana dedicated to producing samarium and gadolinium using a new processing method.
Government backing, however, does not guarantee results. In 2023, Lynas Rare Earths, an Australian mining company, received a Defense Department contract to build a rare-earth processing plant in Seadrift, Texas, but the project was never completed. Instead, Lynas is expanding an existing facility in Malaysia, where it aims to begin separating samarium and other metals by April.
Amid the scramble, there is at least one potentially hopeful development. USA Rare Earth, founded in 2019, has announced plans to build a processing facility in Stillwater, Oklahoma, and recently cleared the final regulatory hurdle to acquire Less Common Metals, Smith's company. If completed, the deal would place a rare Western samarium metallization capability under the control of a US-focused rare-earth developer at a time when the Solvay stockpile is finite.
Image credit: The New York Times