Publications

Frederik Rogiers, PhD researcher and teaching assistant at the Ghent Maritime Institute, has published a new blog post on Opinio Juris. The post - "A Blockade by the Book: Why CENTCOM's Carve-Out for Non-Iranian Ports Matters" - examines the United States' naval blockade of Iran declared in April 2026. It argues that the geographical carve-out preserving access to non-Iranian ports, introduced by CENTCOM within a day of President Trump's announcement of a "blockade of the Strait of Hormuz", is the legal cornerstone on which the lawfulness of the entire operation rests. Working through the conditions for a lawful blockade as developed from the 1856 Paris Declaration through the San Remo and Newport Manuals, he shows how that single textual choice distinguishes a lawful belligerent closure of enemy ports from an unlawful closure of a neutral international strait.

Protest at sea against deep-sea mining is on the rise. Following demonstrations against the activities of Global Sea Mineral Resources (GSR) in May 2021, Greenpeace interfered with the operations of Nauru Ocean Resources Inc. (NORI) in November 2023. The latter case received more media attention, increased involvement by the International Seabed Authority (ISA) and led to a Dutch court decision on the matter, shedding more light on a very complex legal issue. To what extent can such actions be reconciled with the freedom of the high seas? What is encompassed by ‘peaceful protest’ and do these protest activities against deep-sea mining meet the conditions? What other principles and provisions are relevant in these situations and how are these applied? And in case of infractions, which remedies are available and who is responsible to enforce the applicable rules? On the basis of a comprehensive examination of pertinent legislation, official documents and case law, this chapter will offer an insightful view on these issues and the relevant legal developments.

Under the prevailing consensus that Articles 192 and 194(1)(2) of the United Nations Convention on the Law of the Sea (UNCLOS) constitute due diligence obligations as obligations of conduct, small island states have advocated that in the context of climate change, these provisions should go beyond the due diligence obligations and encompass obligations of result. Some even argue that climate change has transformed the nature of these provisions into obligations of result. This paper, drawing upon the reasoning in the recent advisory opinion and analysing the specific rationales advanced by small island states, maintains that neither the concept of due diligence nor the aforementioned provisions of UNCLOS can be interpreted as containing or transforming into obligations of result.
The study emphasizes the critical distinction between the ‘standard of compliance’ for due diligence obligations and independent obligations of result. It further demonstrates that subsequent procedural obligations under Part XII of UNCLOS, along with other rules such as climate targets established by the Paris Agreement, could contribute to clarifying the ‘stringent standard’ of due diligence in climate change contexts. Finally, this paper focuses on achieving systemic coordination between procedural obligations and due diligence requirements, aiming to clarify existing controversies in this field.

Marine Policy

With the oceans covering 70% of the world’s surface, one might be under the illusion that every State might find sufficient space for their activities, nothing could be further from the truth. This was proven once more in January 2022 and August 2023 when Russian vessels sought to engage in military exercises within strategic areas of the Irish and Norwegian exclusive economic zones (EEZs), choosing some of the local fishermen’s preferred locations in the process. Unlike their governments, the local fishermen refused to accept the Russian intrusions and via continuous protest through presence succeeded in forcing the Russian Navy to move the exercises to another area. This example is proof that to this day, the legal framework of the EEZ still gives rise to significant questions and uncertainties, often to the benefit of lawfare lawyers, especially in regards to foreign military activities and overlapping uses of the same area. Art. 56 LOSC awards sovereign resource rights to the coastal State, but arts. 58 and 87 LOSC grant the maritime user State the freedom to navigate. How to reconcile these different uses has for a long time occupied the minds of law of the sea lawyers. In this article, an attempt is made - utilizing a selection of national and international jurisprudence - to clarify the relation between these different uses of the EEZ, their permissibility and why the fishermen’s success in these cases might not so easily be translated into general international law.