One emerging challenge to the rules-based international order is the exploration and exploitation of the mineral resources of the deep seabed pursuant, not to the approval of the International Seabed Authority (ISA), but to the unilateral authorization of a single state, in this case the United States of America.
As we now know, the possibility of unilateral mining, seemingly abandoned in the 1990s, has been running silent for the last three decades. Last year it resurfaced and it is now motoring toward the global commons. This blog post argues that UNCLOS states parties can and must catch up before it reaches its target.
The Challenge
In a story familiar to followers of deep seabed mining, last April the United States resurrected the Deep Seabed Hard Mineral Resources Act (DSHMRA), passed in 1980 as an interim measure to “encourage the successful conclusion of a comprehensive Law of the Sea Treaty, which will give legal definition to the principle that the hard mineral resources of the deep seabed are the common heritage of mankind” (30 USC §1401(b)(1)). Mining under DSHMRA, a statute enacted before the adoption of UNCLOS and the Part XI Implementing Agreement, may contravene US customary international law obligations. Regardless of US obligations however, such unilateral activities in the Area have the potential to engage the obligations of UNCLOS states parties set out in Article 139.
Following the announcement of DSHMRA’s revivification, a cluster of US-incorporated seabed mining interests appeared, including:
- The Metals Company USA (TMC USA) (originally DeepGreen Resources, renamed TMC USA January 2025), a subsidiary of Canada’s The Metals Company (TMC);
- American Metal Resources (AMR) and SeaX, both subsidiaries of US-based American Metal (incorporated January 2025);
- American Ocean Minerals (AOM) (incorporated May 2025), a subsidiary of Canada’s Deep Sea Minerals;
- American Deep Sea Minerals (ADSM) (originally incorporated as Kraken Metals August 2025); and
- Deep Sea Rare Minerals (DSRM) (rebranded Eco Minerals May 2026).
The US National Oceanic and Atmospheric Administration (NOAA) is now awash in applications for exploration licenses and commercial recovery permits in respect of polymetallic nodules in areas of the Pacific Ocean beyond national jurisdiction. According to Erik Noble of NOAA, the agency had received “over 10 applications” by late January 2026. Five exploration license applications have been made public and are moving through NOAA’s review process: two from TMC USA and one each from AMR, SeaX and ADSM.
A Vulnerability
These applicants face a common statutory hurdle: they must demonstrate that, upon issuance of an exploration license, they “will have the technological capability to engage in such exploration” (30 USC §1413(c)(2)).
And their applications expose a common weakness: the applicants do not, themselves, possess the technological capability to undertake the work for which they are applying. Absent possession, they must demonstrate to the NOAA Administrator that they will “have access to or a reasonable expectation of obtaining” the requisite capability (15 CFR 970.402).
In order to demonstrate that they will have such access, the applicants cite their anticipated partnerships with individuals, companies and institutions, the majority of which are nationals of states parties to the Convention.
By way of example, the most recent applicant, ADSM, lists four vessels it has identified as “suitable for supporting the proposed exploration program” (p. 27). Those four vessels are flagged by, and therefore possess the nationality of, the Bahamas, Cook Islands and New Zealand, all UNCLOS states parties.
Such heavy reliance on non-US entities is a substantial vulnerability in the face of UNCLOS states parties’ obligation to ensure compliance with the rules of UNCLOS by their nationals and others. As James Kraska and Digvijay Rewatkar put it:
Absent [incorporation in the U.S.], cooperation with U.S.-based entities may expose private actors to significant domestic litigation risks and, more importantly, expose States parties to international responsibility for breach of their primary and due diligence obligations under UNCLOS (p. 31).
The Obligation to Ensure
The obligation to ensure is set out in the first sentence of the first paragraph of UNCLOS Article 139.
Article 139
Responsibility to ensure compliance and liability for damage
1. States Parties shall have the responsibility to ensure that activities in the Area, whether carried out by States Parties, or state enterprises or natural or juridical persons which possess the nationality of States Parties or are effectively controlled by them or their nationals, shall be carried out in conformity with this Part.
As the 2011 Seabed Disputes Chamber Advisory Opinion clarified, “In article 139 . . . the term ‘responsibility’ means ‘obligation’” (para. 65).
To whose conduct does the obligation apply?
Article 139 enumerates eight categories of actors whose conduct a state party must ensure is in conformity with the Convention:
- the state, itself;
- its state enterprises;
- natural persons who possess the nationality of the state;
- juridical persons who possess the nationality of the state;
- non-national natural persons who are effectively controlled by the state;
- non-national juridical persons who are effectively controlled by the state;
- non-national natural persons who are effectively controlled by a national of the state; and
- non-national juridical persons who are effectively controlled by a national of the state.
Membership in categories 1, 2, 3 and 4 will be determined by reference to international rules of attribution or a state’s nationality laws assessed in light of principles of international law.
Membership in categories 5, 6, 7 and 8will turn on two different tests of effective control, one where a state may control a non-national firm or individual (categories 5 and 6) and another where a firm or individual may control a non-national firm or individual (categories 7 and 8). These four categories have the potential to expand substantially the number of actors whose conduct states parties must constrain.
As regards categories 5 and 6 more specifically, it must be noted that for several years the ISA’s Informal Working Group on Institutional Matters (IWG IM) has considered effective control of a firm by a state in the limited context of state sponsorship of an ISA contractor. The IWG IM has debated the appropriate control test to be applied in these circumstances without yet reaching a definitive conclusion.
In contrast to the relatively narrow considerations within the sponsoring state-ISA contractor relationship, the question of effective control in the context of unilateral authorization of activities in the Area (where there is no sponsoring state) takes on broader proportions: broader in terms of the potential states whose obligations may be triggered, the potential non-state actors whose conduct may be covered and the potential liability that may result from a breach of the obligation to ensure. The context is different, and the control test may also be different.
As regards categories 7 and 8, there is yet another set of relationships that are wholly distinct from the sponsoring state-ISA contractor relationship, but which are also governed by “effective control”, are the relationships between a firm or individual and another firm or individual.
Importantly, among the relationships that could trigger state obligations, is the relationship between a parent company and its subsidiaries. Put differently, a state party has an obligation to ensure conforming conduct by a non-national subsidiary if the parent company (a) is a national of or effectively controlled by that state, and (b) effectively controls its subsidiary. The control test used to identify members of categories 7 and 8, all non-state actors, may require the application of an entirely different control test than that applied to categories 5 and 6.
Which activities are included under the obligation?
The Article 139 obligation to ensure applies to “activities in the Area”, which “means all activities of exploration for, and exploitation of, the resources of the Area” (UNCLOS, Article 1(1)(3) (emphasis added)). The SDC, again in the context of state sponsorship within the ISA framework, opined that “[t]ransportation to points on land” and processing “conducted at a plant situated on land” are “excluded from the expression ‘activities in the Area’” (SDC AO, paras. 95-96).
With those exceptions, the definitional phrase “all activities” casts a wide net. Fisher and Robb would include “contributing necessary and material elements of such an operation such as environmental, engineering and design services, vessels, equipment, bunkering and supplies”; “shar[ing] critical data, designs, personnel”; “[providing] consultancy services”; providing or flagging vessels to be “used as part of any activities in the Area” and “financing activities in the Area”.
Nollkaemper finds that “the development, commissioning and operation of the collection system” are activities subject to Article 139(1).
ISA exploration regulations add “analysis of … deposits”; “testing of collecting systems and equipment”; and “carrying out of studies of the environmental, technical, economic, commercial and other appropriate factors that must be taken into account in exploitation” (Reg. 1(3)(b)).
Lily and Robb ask whether the activities of “sub-contractors, technical advisors, financiers, insurers, ports, logistics providers, [and] shipping registries” might also be included.
What does the obligation require of states parties?
The SDC notes that the obligation to ensure is a “due diligence” obligation that requires states “to deploy adequate means, to exercise best possible efforts, to do the utmost” to ensure conforming conduct by the eight categories of actors listed above (SDC AO, para. 110).
It is an evolving obligation that “may change over time as measures considered sufficiently diligent at a certain moment may become not diligent enough in light, for instance, of new scientific or technological knowledge” (SDC AO, para. 117). The sufficiency of a state’s diligence must now also be assessed in light of the new, potentially system-breaking threat of unilateral activities.
Although the obligation “may not easily be described in precise terms” (Id.), it entails the following:
- “Necessary measures … must be adopted within the legal system of [states parties]” (SDC AO, para. 118);
- A state must “adopt ‘laws and regulations’ and [] take ‘administrative measures which are, within the framework of its legal system, reasonably appropriate for securing compliance by persons under its jurisdiction” (SDC AO, para. 119, quoting UNCLOS Annex III, Article 4(4));
- States must “assist the Authority by taking all measures necessary to ensure such compliance in accordance with article 139” (UNCLOS, Article 153(4));
- A flag state may have a parallel obligation to “adopt the necessary administrative measures to ensure that … vessels flying its flag are not involved in activities which will undermine the flag State’s responsibilities under the Convention” (2015 Sub-Regional Fisheries Commission Advisory Opinion, para. 119);
- “Laws, regulations and administrative measures may include the establishment of enforcement mechanisms” (SDC AO, para. 218); and
- “[S]uch measures should be kept under review” because “the national measures, once adopted, may not be appropriate in perpetuity” (SDC AO, para. 222).
In fact, the majority of UNCLOS states parties have not begun to implement, at the domestic level, their international obligation to ensure. Lily and Robb have teased elements from the few examples of existing domestic legislation, including “[e]xpress prohibition on unauthorized exploration or exploitation” and “[c]riminalisation of violations”. Noting that these examples “predate today’s concrete threat of unilateral DSM in the Area”, they provide additional drafting suggestions.
Because the obligation to ensure reaches the conduct of actors (in categories 5-8) who would fall outside a state’s jurisdiction on the traditional bases of territoriality, nationality, effects or passive personality, states parties may need to adopt measures with extraterritorial implications or exercise direct extraterritorial jurisdiction in order to fulfil this obligation. In the face of the new threat of unilaterally-authorized activities in the Area carried out by multinational corporate groups engaged in regulatory arbitrage, this veil-piercing approach is not only appropriate but necessary to prevent a parent company from accomplishing objectives through a subsidiary that would be illegal under the laws of the parent’s state.
The Article 139 obligation to ensure sets a floor above which states may do more. Although not easily described, it is clear that doing nothing will not meet the bar. Instead, inaction will expose states to litigation for breach of an obligation owed to its treaty partners if not the entire international community.
Breach is Imminent
For those states parties whose nationals (or persons their nationals effectively control) are a DSHMRA applicant, parent of a DSHMRA applicant, in contract with a DSHMRA applicant or named as a potential partner of a DSHMRA applicant, the sand in the hourglass is running low.
They include:
- Australia (ERIAS Group***, AMC Consultants***, Asia Pacific Applied Science Associates, Australian National University, Charles Darwin University, Coffey Natural Systems, Commonwealth Scientific Industrial Research Organization (CSIRO), Curtin University of Technology, Hydrobiology, James Cook University, Nigel Holmes and Associates, Worley Parsons)
- Austria (Voest Alpine)
- Bahamas (Fugro Equator, Fugro Supporter)
- Belgium (Dredging, Environmental and Marine Engineering (DEME), Global Sea Mineral Resources (GSR))
- Canada (The Metals Company (TMC)**, The Metals Company USA (TMC USA)*, Deep Sea Minerals**, American Ocean Minerals (AOM)*, Ocean Floor Geophysics, University of Toronto, Placer Dome, Teck, Barrick, United Nickel)
- Cook Islands (Kiva Marine, R/V Anuanau Moana, Ocean Minerals)
- Denmark (Maersk, Maersk Launcher)
- France (Technip)
- Malta (Hidden Gem***)
- Nauru (Nauru Ocean Resources (NORI)***)
- Netherlands (Allseas***, Fugro, Royal IHC);
- New Zealand (Earth Sciences New Zealand (GNS-NIWA), R/V Tangaroa)
- Norway (Kongsberg)
- Papua New Guinea (Vulcanology Experts, University of Papua New Guinea, Rabaul Volcano Observatory)
- Singapore (Deep Green Engineering)
- Switzerland (Allseas***, Glencore***)
- Tonga (Tonga Ocean Minerals (TOML)***)
- United Kingdom (Natural History Museum, University of Southampton, National Oceanography Centre, Soil Machine Dynamics, Perry Slingsby Systems, Anglo American)
* DSHMRA applicant; ** parent of DSHMRA applicant; *** in contract with DSHMRA applicant.
[Links to DSHMRA applications can be found HERE. This list does not include the many natural persons who intend to carry out activities in the Area pursuant to US authorization.]
States Parties Must Act
Among some quarters there is a sense that if only the ISA would finally conclude its exploitation regulations, the threat of US-authorized mining would magically fall away. TMC has deployed this narrative to justify its change of course from the ISA to the USA, but even casual observers of the current US administration will understand that no amount of drafting or decision-making in Kingston will change hearts and minds in Washington.
Others might hope that if the Authority would deny contract extensions to TMC’s subsidiaries NORI and TOML, TMC’s investors would flee and TMC’s project would fail. While such a rejection should negatively impact TMC share prices, the effect might be dampened by the hype around critical materials and the apparent momentum behind the US unilateral mining route.
Finally, some hope to run out the clock on the current US administration, after which the world as we remember it will snap back to its previous shape: another risky bet.
Ultimately, it is unhelpful to frame the current situation as a race between the ISA and USA. It is better characterized as a race between the unfettered ambitions of the United States and the legislative dexterity and political will of states parties to the Convention.
As states begin to implement their obligation to ensure, several questions remain: How broad or narrow is the scope of activities encompassed by the terms “activities in the Area” and “carried out”? What test or tests will be used to define “effective control” between state and firm and between firms in the ISA sponsorship and USA unilateral contexts? Which domestic laws, regulations, administrative measures and enforcement mechanisms will states adopt in order to fulfil their international due diligence obligation? How will states ensure with respect to individuals and firms beyond their borders? And will their treaty partners invoke compulsory dispute settlement in the event of breach?
Irrespective of the answers, the US strategy has a critical weakness. States parties have the tools to exploit that vulnerability and to defend rule of law on the seabed. Should they choose to use those tools, states parties must act quickly to prevent all eight categories of actors from participating in partnerships with the growing number of US entities seeking to make an end run around multilateral ocean governance and the common heritage of humankind.