This blog post was originally published at the AsianSIL Voices blog, and adapted from the author’s presentation at the 10th Biennial Conference of the Asian Society of International Law in Hanoi, Vietnam from 9 to 10 October 2025.
My goal in this short essay is to spark a discussion on how we might rethink the legal standards governing the precautionary principle and the principle of environmental impact assessment (EIA) in the context of deep seabed mining in areas beyond national jurisdiction. In particular, I examine this issue through the lens of judicial review, exploring what insights can be drawn from other legal regimes, such as the climate change framework, as well as from landmark decisions of domestic courts in the developing world.
Recent Developments: President Trump’s Executive Order, TMC US’ applications, and the ISA’s statement
On 24 April 2025, U.S. President Donald Trump issued an Executive Order authorizing American companies to apply for exploration licenses and commercial recovery permits in areas beyond national jurisdiction through the National Oceanic and Atmospheric Administration (NOAA). Just a few days later, on 29 April 2025, the U.S. subsidiary of The Metals Company (TMC) submitted two applications for exploration licenses to the U.S. government. These applications cover areas located in the Clarion-Clipperton Zone in the North Pacific Ocean, with a combined total area of approximately 199,895 square kilometres.
Following President Trump’s Executive Order and the subsequent exploration license applications by TMC’s US subsidiary, the International Seabed Authority (ISA) swiftly issued a statement warning that any unilateral action could undermine the fundamental principles that have guided deep-sea governance for decades. ISA Secretary-General Leticia Reis de Carvalho warned that such unilateral actions would amount to a violation of international law.
These developments raise profound and unsettling questions under international law. Is the Executive Order a clear violation of international law, or does it simply expose the limits of international legal authority over states that have chosen to remain outside the UNCLOS framework? How far does international law truly reach when dealing with a powerful non-party state, and what does this mean for the legitimacy of global ocean governance? Equally compelling is the question of how international law can or should regulate non-state actors, such as deep-sea mining corporations and private contractors.
The Mining Code and the Draft Exploitation Regulations: Standing Issues
The ISA is currently in the process of finalising the Mining Code, particularly the section on Exploitation Regulations. The Mining Code as a whole consists of three main components: (1) the Regulations on Prospecting, (2) the Regulations on Exploration, and (3) the Regulations on Exploitation. The first two sets of regulations were adopted between 2010 and 2013, but the third and most critical component remains under negotiation.
The draft Exploitation Regulations is a massive document, containing over a hundred provisions, many of which remain highly contested. In this essay, I focus particularly on the debates surrounding inspection, compliance, and enforcement mechanisms, as well as the question of effective control by states.
Four General Observations
(1) Uncertainties in Operationalising Precautionary Principle
Although the draft Exploitation Regulations place considerable emphasis on the precautionary principle and EIA, they offer little concrete guidance on how these principles should be applied in practice and balanced in case of conflict. It remains unclear how the precautionary principle should be operationalised — a significant gap in the current Mining Code. This issue is especially critical given the possibility of unilateral mining activities and the active involvement of private corporations and contractors.
(2) Situating Precautionary Principle and EIA within Rules on Regulatory Due Diligence
I argue that Precautionary Principle and EIA should be situated within the broader framework of due diligence and, ultimately, state responsibility for internationally wrongful acts. Recent advisory opinions on climate change by the ICJ and ITLOS offer valuable lessons. The ICJ has held that the duty to prevent environmental harm is an obligation of due diligence (para 280) and that this duty has attained the status of customary international law (para 272). A state that does not act with due diligence to prevent environmental harm commits an internationally wrongful act (see para 409). Read through this lens, the precautionary principle and EIA are core elements of the due-diligence duty — requiring states to anticipate and assess risks, use the best available science, adopt effective regulatory measures, and halt activities where serious or irreversible harm is plausible.
(3) Elements of Regulatory Due Diligence
Both the ICJ and ITLOS advisory opinions have elaborated on the specific elements that constitute regulatory due diligence. The ICJ identified several factors, including the establishment of a comprehensive EIA system and the application of measures consistent with the precautionary principle (see paras 280–300). Crucially, the Court emphasized that due diligence is not merely about adopting abstract commitments but about building and maintaining a functioning national regulatory framework — comprising legislation, administrative procedures, monitoring institutions, and enforcement mechanisms. This insight has particular resonance for developing states, which often find themselves both resource-dependent and regulation-constrained.
(4) Drawing Lessons from Domestic Courts
International law can also learn from the experience of domestic courts in interpreting and applying the precautionary principle and EIA in environmental disputes. National judiciaries have often been more innovative and pragmatic than international tribunals in giving concrete meaning to these principles. Several domestic decisions have held that defects or omissions in an EIA may amount to a breach of the precautionary principle itself — recognising that a flawed assessment undermines the very purpose of precaution. These jurisprudential developments offer valuable insights: they remind us that precaution is not merely a procedural step, but a substantive commitment to protect the environment amid uncertainty.