From Mare Liberum to Make America Great Again

In April 2025, US President Donald Trump issued an executive order titled Unleashing America’s Offshore Critical Minerals and Resources, instructing the National Oceanic and Atmospheric Administration (NOAA) to fast-track licenses for seabed mining beyond national jurisdiction. The announcement came just weeks after The Metals Company (a Canadian firm long embedded in the International Seabed Authority (ISA) process through Pacific Island sponsorship) signalled its pivot to a unilateral US-based application for a deep-sea mining license. If the formal rhetoric of the order spoke the language of energy dominance and technological leadership, its legal gesture reached further back: a return to the high seas as a domain of open appropriation, a space where jurisdictional constraint gives way to national will.

The international reaction was swift. At the ISA’s 30th session, states invoked customary law, the common heritage of humankind, and the integrity of the global seabed regime. In June 2025, the UN Ocean Conference (UNOC3) opened in Nice with renewed calls for multilateral stewardship and ecological restraint, culminating in the Nice Ocean Action Plan. In the diplomatic choreography of ocean governance, this sequence of moves and countermoves might appear as simply another contest between unilateralism and multilateralism. But the deeper stakes lie elsewhere. Trump’s executive order is not a departure from institutional consensus. It is a reactivation of a much older legal imaginary – one that casts the ocean as a site of liberty, extraction, and sovereign ambition.

This text traces a through-line from Hugo Grotius’ Mare Liberum to Trump’s 2025 order, identifying what might be called a neo-Grotian logic of seabed mining. It argues that the apparent conflict between Trump’s move and the law of the sea regime is, paradoxically, also a moment of legal continuity: a reaffirmation of the law’s long-standing capacity to render the ocean as a space of sacrifice.

Grotius and the Invention of the Boundless Ocean

When Hugo Grotius penned Mare Liberum in the early seventeenth century, he did not merely defend the Dutch East India Company’s commercial access to Asian waters. Grotius inaugurated an enduring legal imaginary of the sea. His sea was open not only in a jurisdictional sense but in an ontological one: unpossessable, inexhaustible, and immune to enclosure. Grotius’ argument that “every nation is free to travel to every other nation, and to trade with it” rested on a deeper presupposition; that the ocean itself was a medium that could neither be occupied nor exhausted, and thus was by nature suited to circulation and use.

This conception was not an empirical description of maritime reality. It was a juridical worldmaking act: a normative projection onto space that rendered the sea governable through the legal grammar of freedom. In denying territoriality, Grotius secured not oceanic restraint but extractive access: the freedom to navigate was simultaneously the freedom to take. The sea’s legal unboundedness became a proxy for its economic availability.

In this sense, Mare Liberum established more than a rule – it founded a genre of legal thought, one in which the sea could be imagined as legally useful only when open to exploitation. This imaginary would sediment into doctrine and circulate through centuries of maritime law, resurfacing in the high seas freedoms of the 1958 Geneva Conventions and surviving, albeit refracted, within the compromises of UNCLOS. That it now returns under the imprimatur of a US presidential order is not a rupture with the history of international law but a reminder of how enduring its imaginative boundaries can be.

From Freedom to Management: The Enduring Logic of Availability

The transition from Grotius’ boundless sea to the managed spaces of UNCLOS is often cast as a story of legal maturation: freedom tempered by responsibility, sovereignty checked by cooperation. But this narrative obscures a deeper continuity. Even as the modern law of the sea institutionalised new constraints, the underlying imaginary of availability endured. The ocean remained legible to international law primarily through its capacity to be used.

Nowhere is this clearer than in the legal architecture of deep-sea mining. While UNCLOS proclaimed the Area and its resources the common heritage of humankind, it did not invert the Grotian premise so much as domesticate it. Through the machinery of the ISA, seabed resources would not be shielded from extraction but allocated under multilateral management. The promise of shared benefits preserved the extractive horizon and promised to redistribute its dividends. Technical terms like “exploitation regulations,” “sponsoring states,” and “benefit-sharing” thus sustained the deeper legal fiction: that the ocean floor could be rationally governed without challenging the primacy of access.

Note, however, that this shift from freedom to management did not constitute a rupture in international law’s orientation to the sea, but a recalibration. It displaced the figure of the merchant with that of the administrator but kept the seabed as an object of value and intervention. That the United States (though a non-party to UNCLOS) could so swiftly revive a unilateral licensing regime under domestic law in 2025, despite decades of active participation in the institutional life of the ISA, reveals a deeper ambivalence. For decades, the US had largely behaved itself as a de facto supporter of the Convention’s framework, including a July 2024 declaration of support for the ISA’s regulatory efforts and stated commitment to its “30 years of work to develop the legal framework for the Area.”  But the reassertion of domestic authority through the 2025 executive order suggests that this support might have been conditional—less a settled Republican orientation than a contingent artifact of the diplomatic veneer of prior Democratic administrations. What it exposes is not just the fragility of multilateralism, but the shallow internalisation of the legal imaginary of collective stewardship. In short: if the Grotian sea was boundless, the Trumpian sea is open to appropriation.

Trump’s Decree as Neo-Grotian Legal Performance

President Trump’s April 2025 executive order did not emerge in a legal vacuum. It drew upon the Deep Seabed Hard Mineral Resources Act (DSHMRA), enacted in 1980 as a stopgap during the waning days of the UNCLOS negotiations. Framed at the time as an interim measure “to encourage the successful completion of a comprehensive Law of the Sea Treaty,” DSHMRA authorised the US to issue seabed mining licenses unilaterally—an authority that had remained dormant for decades. That it could now be reactivated by presidential fiat is no longer merely a bureaucratic curiosity.

The Executive Order’s rhetorical gestures of “unleashing” offshore minerals and restoring US energy leadership are familiar features of Trump’s populist governance style. But its legal content reveals something more enduring: the reanimation of an old imaginary, one in which the ocean floor is not a commons to be collectively managed but a frontier to be individually claimed. In this sense, Trump’s order is not anti-law but neo-Grotian. It echoes Grotius’ presumption that the high seas, by virtue of their openness, invite and legitimate acts of extraction. The assertion of a national right to mine beyond jurisdiction is framed more than just defiance of international law, but as an expression of a higher constitutional-legal principle – freedom.

This is more than rhetorical sleight of hand. It reflects a structural possibility within the law itself: the coexistence of contradictory norms, the selective invocation of customary principles, and the reliance on historical precedent to authorize contemporary disruption. In Trump’s decree, legal form cloaks geopolitical ambition. The seabed is rendered not just accessible but grabbable. Again, if Grotius made the sea free for trade, Trump makes it free for appropriation.

Final Remarks: Undoing the Boundless

What Trump’s executive order lays bare is not merely a political rupture, but a legal continuity too seldom interrogated. Across the span from Mare Liberum to MAGA, the law has served not only to constrain action but to imagine space. The sea was never simply “free” in the neutral sense; it was made free for certain kinds of uses, certain forms of mobility, and certain extractive logics. The shift from imperial navigation to corporate seabed mining is not a deviation from legal form, but its latest expression. Even in the era of the common heritage, the ocean remains configured as something to be accessed, used, and optimised.

To recognise this is not to deny the real stakes of recent developments, nor to collapse all legal imaginaries into one. Rather, it is to foreground the epistemic violence of legal continuity – the way in which international law reproduces the very conditions it purports to regulate. Multilateral institutions may resist Trump’s unilateralism, but they do so often from within the same framework of availability, merely rebranded as equitable access or regulated growth. The problem, then, is not only one of institutional design or treaty compliance. It is the deeper question of how the law imagines the sea in the first place.

Undoing the boundless requires more than better rules. It demands a different legal imaginary. One that treats the ocean not as a space of latent value, but as a domain of limits, interdependence, and restraint. Until such an imaginary is possible, the seabed will remain what it has long been in legal thought: a surface onto which power projects its future.