Can Multilateralism Survive Deep Seabed Mining Race?

The deep seabed is becoming a new arena of great power competition. China has consolidated its role as the largest contractor in the International Seabed Authority, while the United States, under President Donald Trump, is moving toward unilateral licensing. These developments highlight the growing tension between national approaches and multilateral governance.

In 2025, the debate has intensified. The ISA confronts the expiry of its “two-year rule,” obliging it to consider exploitation applications even without a completed Mining Code. Pacific Island states — alarmed by potential ecological destruction — have spearheaded calls for a moratorium, supported by the European Union and environmental NGOs. Yet their voices are often drowned out by the strategic imperatives driving major powers which increasingly frame the seabed as a strategic reservoir of critical minerals essential for clean energy, advanced manufacturing and defence supply chains.

China stands out as the most active player. It holds the largest number of ISA exploration contracts, covering polymetallic nodules, sulphides and cobalt-rich crusts in the Pacific and Indian Oceans. It also invests heavily in mining technology and research, framing its approach as consistent with United Nations Convention on the Law of the Sea  (UNCLOS) principles and the notion of the seabed as the “common heritage of mankind.” By working through the ISA, China portrays itself as a defender of multilateral governance even as it positions state-owned enterprises and research institutes to secure privileged access to future resources.

The United States, having never ratified UNCLOS, lacks direct influence over ISA decision-making, though it remains active in ISA meetings as an observer. Under Trump’s second administration, frustration with slow-moving processes has fueled unilateral measures. Recent executive orders authorize domestic licences for U.S. companies to mine in international waters, bypassing the ISA altogether. This signals a preference for national jurisdiction and private enterprise over collective rule-making. For U.S. policymakers, the seabed is a critical domain of competition with China, one that, in Washington’s view, warrants extraordinary measures to secure supply chains and technological leadership. This approach came under sharp criticism during the 30th session of the ISA Assembly, where many member states condemned the actions of The Metals Company USA LLC (TMC USA) for attempting to sidestep the ISA framework.  

Strategic implications manifest in distinct ways. For China, alignment with the ISA reinforces its image as a rule-abiding power while securing long-term resource rights. For the United States, unilateralism offers speed and flexibility but risks eroding institutional legitimacy. In his speech at the UN General Assembly on September 23, President Donald Trump underscored this unilateralist posture by slamming global institutions, rejecting renewable energy, and condemning the UN’s support for refugees and migrants. By contrast, President Xi Jinping has repeatedly endorsed multilateralism, most recently at the September 2025 BRICS Summit, where he urged members to “jointly defend multilateralism and the multilateral trading system” and safeguard an international order based on international law. Such rhetoric has reinforced China’s reputation among some observers as a steady hand in support of multilateral governance.

For East Asian middle powers like Japan and South Korea, the dilemma is acute. Both possess technological expertise and interest in seabed minerals, yet must balance support for multilateral rules with their security ties to Washington. Smaller, resource-dependent states in the Pacific and Indian Oceans face particularly stark choices. China has integrated seabed resource cooperation into its Belt and Road Initiative, embedding joint exploration, port development, undersea cable infrastructure, and maritime research into broader financing packages. Such arrangements promise immediate infrastructure gains but raise concerns about debt exposure and political dependency. The United States promotes the Mineral Security Partnership with selected democracies and mineral-rich partners, framing seabed cooperation around supply chain resilience, transparency, and environmental sustainability.

As competition for critical minerals intensifies, deep-sea mining governance reflects two contrasting approaches: a near-universal regime anchored in UNCLOS and the ISA, and a unilateral U.S. path shaped by domestic law and executive orders. Yet the deeper divide is less “U.S. versus China” than “U.S. versus the rest of the world,” as most other major powers, including U.S. allies, continue to operate within the UNCLOS framework.

This divergence highlights the dual challenge for the ISA: reconciling divergent state preferences while strengthening ecological safeguards. Neither unilateral action nor institutional dominance alone can resolve deep uncertainties about the environmental consequences of seabed mining.

Looking ahead, progress cannot rest on China and the United States alone. ISA remains central to translating the broad obligations of UNCLOS into binding and enforceable standards. Pacific Island states, acting as key sponsors of exploration contracts, will continue to press for stronger environmental safeguards to protect their fragile marine ecosystems. European states, particularly Germany and France, are expected to champion precautionary approaches and higher thresholds for environmental impact assessments. Major resource consumers such as India and Japan will push for predictable rules that secure long-term access to critical minerals essential for their energy transitions and industrial supply chains. Still, U.S. and Chinese choices remain decisive. As the world’s two largest economies and technological leaders, their willingness to invest in ISA processes, comply with its standards, and coordinate—or compete—in shaping rules will ultimately determine both the Authority’s credibility and the broader viability of a universal regime for deep seabed governance.

The result is a fragmented governance landscape where multilateralism, unilateralism, and environmentalism collide. Deep-sea ecosystems remain poorly understood, and mining risks irreversible consequences — from biodiversity loss to the disruption of carbon sequestration. For resource-dependent economies, these dangers are immediate: environmental degradation threatens marine food security, while regulatory uncertainty fuels geopolitical friction and complicates investment decisions.

Managing these challenges will require pragmatic strategies. Governments can back reforms to make the ISA more transparent and accountable, while boosting investment in marine science to ensure decisions rest on credible data. They can also coordinate through regional and multilateral forums to amplify their influence, while diversifying critical mineral supply chains to reduce vulnerability to seabed mining or single-source dependence. Such measures will not resolve every tension, but they can help states hedge against both environmental damage and strategic coercion.

The seabed is more than a new resource frontier; it is a test of whether multilateral rules can withstand the strain of great-power rivalry. The choices made today will decide not only who gains access to critical minerals, but whether the idea of a rules-based order can survive in one of the world’s last true global commons.