Beneath the vast expanse of the Pacific Ocean lie small, black, potato-sized treasures - polymetallic nodules rich in valuable metals and rare earth elements - waiting to be unearthed.
Strewn across the sea floor of the Pacific, Atlantic and Indian oceans, the coveted nodules and other forms of ocean deposits are gaining widespread attention. Yet for all their vast potential, deep-sea mining remains off-limits for now.
The obstacle is not merely technological feasibility but a lack of legal clarity.
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Under the United Nations Convention on the Law of the Sea (Unclos), resources in international waters are deemed the common heritage of humankind, belonging equally to all countries regardless of their geographic position or technological capabilities.
Unclos states that the commercial exploitation of seabed minerals can only begin with the establishment of a general mining code, a comprehensive set of legal, environmental and operational regulations.
This task falls to the International Seabed Authority (ISA), a UN agency. However, the code's finalisation has stalled within the ISA framework, largely due to mounting environmental concerns.
While China is a dominant supplier of many critical minerals and most rare earths, the US is looking to reduce its reliance on the Asian economic giant. Deep-sea mining has rapidly emerged as one way Washington could do just that.
Amid the ISA impasse, the US announced in April that it would fast-track the commercial exploitation of seabed resources in not only its exclusive economic zone but also international waters. The US is not a full ISA member and has yet to ratify Unclos.
Policy analysts have warned that Washington's unilateral approach risks setting a precedent for other nations to bypass the ISA framework.
America's push could also undermine a framework that Beijing has heavily invested in shaping and possibly leave China lagging behind other countries in exploiting resources in international waters, they added.
According to Unclos, in effect since 1994, countries can exclusively access minerals within their 200-nautical mile continental shelves.
They can also access resources on their "extended continental shelf", which can run to 350 nautical miles. But they must share a portion of their revenues, distributed by the ISA.
Meanwhile, the ISA regulates and exclusively oversees the exploration and development of deep-sea mineral resources located in areas beyond national jurisdiction.
To date, more than 30 exploration contracts have been awarded, with Chinese state-owned enterprises and research institutions holding five of them - the highest total among Unclos member states.
Chinese entities have also secured the largest total area for exploration, according to analysts who have described Beijing as being committed to a long-term vision for the ISA.
Isaac Kardon, a senior fellow for China studies at the Carnegie Endowment for International Peace, a US think tank, said China was the biggest power involved in ISA negotiations and had made consistent contributions to the agency that increased Beijing's overall influence.
Those efforts included building facilities at ISA's headquarters in Jamaica, hosting and training maritime experts at China's lone ISA technical training facility and being the ISA's top patron, Kardon added.
Through its consistent and long-term participation in the ISA, China has positioned itself as a major player in the field of deep-seabed mining. It is the only major country that has remained involved in making the ISA's mining code rules, according to analysts.
Zheng Zhihua, an associate professor specialising in maritime law at Shanghai Jiao Tong University, described China's strategy in deep-sea mining as multilateralism with a strategic calculation.
"By engaging in the ISA process deeply, Beijing seeks to expand its influence in rule making and ensure that its voices and interests will be better reflected," Zheng said.
Subsea minerals usually consist of polymetallic nodules, polymetallic sulphides and cobalt-rich crusts. Among these, polymetallic nodules are considered the closest to commercial viability.
A subsea collector picks up the nodules from the sea floor, and the material is later processed to extract critical mineral resources, including rare earth elements.
Deep-sea mining unlocks access to a range of critical minerals and rare earth elements, such as cobalt, nickel and copper. These propel modern technologies, such as electric vehicles and steel production.
Yttrium, lanthanum, cerium and neodymium are among the rare earth elements embedded in these deep-sea deposits.
Despite progress in exploration, the ISA has yet to authorise any commercial mining activities. Approval hinges on the adoption of the long-overdue general mining code.
For entities eager to venture into deep-sea mining, the lack of clear regulations creates substantial uncertainty, according to Xu Xiangxin, an associate professor specialising in the law of the sea and international law at Shanghai Jiao Tong University.
"For enterprises, in the absence of regulations, environmental requirements also remain uncertain, and these requirements are closely related to their financial and technical capabilities," Xu said. "Without legal clarity, moving forward [with] deep-sea mining becomes a daunting challenge for companies."
In addition, rising frustration over the rule-making process has driven some in private industry to side with Washington.
In April, US President Donald Trump issued an executive order directing US government agencies to streamline the process for granting exploration licences and mining permits in areas located beyond America's national jurisdiction.
Soon after the April order, the US branch of The Metals Company, a Canadian firm, applied for a licence to mine the Pacific Ocean's deep seabed as well as two exploration applications in the ocean's Clarion-Clipperton zone (CCZ).
In August, a US agency told the company it was in full compliance and had priority rights over exploration areas in the CCZ.
"Together, the resource [in the exploration areas] is estimated to contain approximately 15.5 million tonnes of nickel, 12.8 million tonnes of copper, 2.0 million tonnes of cobalt and 345 million tonnes of manganese," The Metals Company said in a statement in April.
America's actions could undermine China's long-term bid to shape the rules for deep-sea mining within the multilateral framework, analysts warned.
"If the general mining code remains under negotiation, it effectively prevents China and other ISA member states from advancing commercial seabed exploitation, while other countries, following their own rules, can still press ahead," Xu said.
She added that failing to do so would diminish the principle of "the common heritage of mankind" to mere rhetoric, and weaken environmental protections through unregulated development in the absence of coordinated international regulations.
"Uncontrolled mining activities would potentially transform the international seabed area into an unregulated 'Wild West', as described by UN Secretary General Antonio Guterres," Xu said.
Accordingly, Beijing could face pressure to recalibrate its strategy in the future, according to Hong Nong of the Institute for China-America Studies, a US-based think tank.
"Should the legitimacy and authority of the ISA be undermined, the institutional predictability upon which China's existing exploration contracts and investments rely would be jeopardised," Hong wrote in an article in June.
"China's main goal remains the adoption of a comprehensive mining code, but if the unilateral approach gains traction, it cannot be ruled out that Beijing may consider whether it can prevent this or pursue its own actions," Xu said.
Tom LaTourrette, an expert on critical mineral supply chains at the Rand Corporation, a US-based think tank, said Washington's moves would "incentivise some other countries to follow" it and noted several countries already had their own existing domestic mining regulations.
"We have conflicting regulatory regimes out there. If one operation is licensed by the US and then another operation nearby is operating under the ISA licence agreement, then they are not synchronised or coordinated," LaTourrette said.
That could result in problems such as different environmental standards or even lead to disputes when mining activities were active, he added.
The Metal Company's application areas, for instance, overlap with regions governed by the ISA, amounting to a conflicting regulatory framework.
Analysts have also cautioned that unilateral actions by the US could encourage countries frustrated by the ISA's stalled rule-making process to stop waiting for licensing and regulations from the body.
"This challenges Unclos as the 'constitution for the oceans' and creates a conflict between US law and international law," Kardon said.
Zheng echoed that assessment, saying the US effectively bypassed the ISA's multilateral framework, with Washington and Beijing taking opposite approaches to deep-sea mining governance: one favouring a unilateral path while the other pursued multilateralism.
Washington could eventually harm itself with unexpected moves, Kardon said, warning that Beijing would "stand to reap a passive benefit" if Washington went ahead and licensed The Metals Company to mine in an ISA block.
"Beijing would enjoy, entirely for free, a lofty diplomatic platform to condemn the US as the 'true violator of international law and the real villain of the law of the sea'."
"Rather than being ostracised for its own outlandish nine-dashed line claim and aggressive grey zone operations, China could position itself as the responsible great power in maritime affairs that matters," he continued, referring to Beijing's disputed territorial assertion in the South China Sea.
Beijing could "position itself to lead the Unclos system's 'progressive development' in directions even more challenging to US interests", Kardon added.
A US licence for commercial exploitation would mean the creation of an alternative and potentially illegal deep-sea mining framework, he said, "accelerating the fragmentation of the international legal system".
Kardon said Washington should take a more measured approach, declaring exclusive economic zones for itself and its partners. He said this would be a more suitable and strategic starting point for the commercial production of deep-sea minerals.
However, Xu said the effect of the US accumulating requests for deep-sea mining had yet to be felt despite Trump's executive order in April, adding that companies were looking for a stable long-term policy.
"Under the ISA framework, operations are legal and well-grounded," Xu said. "While Washington may currently support industry development unilaterally, a withdrawal of such support in the future would pose significant risks for companies." Source: South China Morning Post