In August 2026, Japan and the United States worked together to explore extracting rare-earth-rich mud from the seabed near Minamitorishima. It offered a glimpse into the next phase of critical minerals competition. The race for rare earths is no longer confined to land mines and export control policies. As deep-sea minerals become part of national security planning, maritime spaces that were once mainly discussed in terms of sovereignty, shipping lanes, and fisheries may acquire a new layer of strategic value.

The South China Sea is not currently central to China’s rare earth advantage, but it may become increasingly relevant to how Beijing and its competitors think about the future geography of critical minerals security.

For now, China’s rare earth strategy and its South China Sea strategy remain largely distinct. China’s leverage in rare earths comes less from pure geology than from the country’s dominant position in refining, separation, and magnet production, combined with regulatory instruments that allow Beijing to manage outward flows of selected minerals. The April 2025 export control measures on several medium and heavy rare-earth-related items underscored how critical minerals have become part of China’s national security toolbox. 

By contrast, the South China Sea has traditionally been discussed and understood through a different strategic vocabulary: sovereignty claims, maritime jurisdiction, military presence, fisheries, hydrocarbons, and sea lanes of communication. This kind of separation, however, may not hold indefinitely, because the critical minerals competition is acquiring an increasingly prominent maritime dimension. 

As governments search for ways to reduce dependence on existing rare earth supply chains, attention is gradually shifting toward deep-sea muds, polymetallic nodules, cobalt-rich crusts, and other seabed resources. These resources are not immediate substitutes for today’s land-based mines and processing systems, but they are entering strategic planning and industrial policy. Once critical minerals are imagined not only as terrestrial commodities but also as seabed resources, the boundary between resource security and maritime security begins to blur.

The South China Sea disputes have always had a strategic dimension, in addition to the sovereignty disputes alone. Yet oil, gas, fisheries, and shipping are the dominant drivers of maritime competition; seabed resources have thus far remained a less developed part of the story. Studies of Fe-Mn crusts and polymetallic nodules in the South China Sea have identified the presence of cobalt, nickel, rare earth elements, yttrium, and other critical materials. 

That does not mean that the South China Sea is about to become a commercially viable rare earth mining zone. But as deep-sea mineral technologies and governance frameworks mature, the South China Sea’s significance may be reinterpreted through the language of critical minerals security.

That shift, if it occurs, would not replace the existing logic of South China Sea competition but add another layer to it. Critical minerals could make seabed mapping, marine scientific research, environmental regulation, and deep-sea mining rules more politically sensitive. Activities that once appeared primarily scientific or commercial could come to be viewed through the lens of supply chain resilience and national security. 

China is especially well placed to think across these domains because it already possesses capabilities on both sides of the equation. It is not only a central actor in the rare earth supply chain, but also an active participant in deep-sea exploration and seabed governance. China adopted a national law on deep seabed resource exploration and development in 2016. Chinese entities already hold exploration contracts with the International Seabed Authority for polymetallic nodules, polymetallic sulphides, and cobalt-rich Fe-Mn crusts. Its deep-sea technological capacity has also expanded, symbolized by the Fendouzhe manned submersible’s dive to more than 10,000 meters in the Mariana Trench. 

Rare earths are not about to become the central driver of South China Sea disputes. The more important trend is that two strategic arenas for competition are beginning to converge. China’s rare earth strategy is about control over critical supply chains, while its South China Sea strategy is about control over maritime space, rights, and access. As critical minerals competition expands offshore, these two forms of strategic control may begin to interact. The South China Sea, in the longer term, may become part of a broader debate over who maps, governs, regulates, and eventually exploits the seabed resources that underpin future industrial and military power. 

Rare earths may not define the South China Sea today, but they could help reshape how its strategic value is imagined tomorrow.