Murky Waters: Jurisdictional Gaps in the Protection of Critical Undersea Infrastructure

In 1851, the first undersea telegraph line was laid between England and France.[1] By the late 1800s, an extensive transatlantic telegraph system had formed.[2] Today, the complex web of submarine telecommunications cables, pipelines, and energy installations that supports global communications and energy networks is known as critical undersea infrastructure.[3] This infrastructure has become increasingly vulnerable to accidental damage and intentional sabotage in an age of increased maritime traffic and international conflict.[4]

Damage to undersea infrastructure is usually accidental and can result from fishing activity or the dragging of a ship’s anchor.[5] This is especially true of telecommunications cables, which are typically more easily damaged than energy pipelines.[6] However, European security officials and defense analysts increasingly warn that these structures have become targets of international sabotage.[7] Since the start of Russia’s invasion of Ukraine, there have been a number of cases of damage to infrastructure in the Baltic Sea.[8] For example, on Christmas Day 2024, the Estlink 2 power cable running between Finland and Estonia was severed.[9] Finnish authorities charged crew members of the Cook Islands-flagged oil tanker Eagle S with sabotage and communications interference.[10] The Eagle S is suspected to be part of Russia’s “shadow fleet,”[11] which consists of hundreds of aging tankers used to avoid western-imposed sanctions by flying flags of convenience from places like Gabon or the Cook Islands.[12] A Helsinki District Court later dismissed the case, arguing it did not have jurisdiction over the defendants.[13] Similarly, Chinese vessels have severed cables in the East China Sea that provide links to Taiwan.[14] Although no direct evidence ties the Chinese government to the incidents, Taiwanese officials believe the damage is part of a harassment campaign by China.[15]

The current international regime governing the protection of critical undersea infrastructure is, like the waters of the Baltic Sea, quite murky.[16] International law was first applied to undersea infrastructure in the 1884 Convention for the Protection of Submarine Telegraph Cables, which declares it a punishable offense to willfully or negligently damage undersea telegraphic communications.[17] Enforcement under this treaty is weak, as only the vessel’s flag state or the offender’s state of nationality has authority to prosecute violations.[18] Undersea infrastructure is also governed by the United Nations Convention on the Law of the Sea (UNCLOS).[19] Under UNCLOS, the jurisdiction of a state extends twelve nautical miles off their coasts, an area referred to as the “territorial sea.”[20] Beyond these territorial waters is a 200-mile Exclusive Economic Zone, where states enjoy exclusive rights to natural resources and the power to take measures to protect those rights.[21] When cables are damaged, governing laws vary depending on where the cables are laid.[22] A coastal state has sovereign rights in its territorial sea.[23] While coastal states and private firms who own undersea cables have rights under UNCLOS to repair and maintain cables in the EEZ, it is not clear that states have any prosecutorial powers within this zone.[24] Beyond 200 nautical miles, only flag states have clear jurisdiction over offenders.[25]

Increased observation by international bodies may have some deterrent effect on cable incidents.[26] In January 2025, NATO launched the “Baltic Sentry,” a surveillance mission that uses frigates, aircraft, and drones to observe and protect critical infrastructure.[27] However, the Baltic Sentry is limited in the actions it may take against suspicious vessels.[28] In the event that aggressive states are not deterred by such measures, international law should be strengthened to provide for more effective prosecution of offending parties.[29] Although increasing division within the UN could make drafting a new regime difficult, the specter of hybrid warfare and global communications disruptions could push the passage of new agreements.[30] A practical reform would be to authorize both the cable owner’s state and the offender’s flag state to exercise jurisdiction over violations involving submarine cables.[31] This increased vulnerability may make unintentional perpetrators more careful and intentional saboteurs more wary.[32] If international bodies cannot come to new agreements, it may be possible for states to reinterpret UNCLOS as providing for enforcement jurisdiction within EEZ zones.[33] Coastal states could argue that cable damage creates rights under the convention’s environmental protection provisions, in the case of energy pipelines, or under its piracy provisions, in the case of intentional sabotage.[34] These interpretations, however, have yet to be tested.[35]

Anthony Trabucco is a staff member of Fordham International Law Journal Volume XLIX. 

[1] See Mid-Atlantic Regional Council on the Ocean & Mid-Atlantic Regional Planning Body, Critical Undersea Infrastructure, Status, Trends & Linkages (Mid-Atlantic Regional Council on the Ocean, Mid-Atlantic Regional Ocean Assessment 2016), https://roa.midatlanticocean.org/ocean-uses/status-trends-and-linkages/critical-undersea-infrastructure/ (last accessed Nov. 10, 2025).

[2] See Windward Ltd., What Is Critical Undersea Infrastructure?, Windward AI Glossary, https://windward.ai/glossary/what-is-critical-undersea-infrastructure/ (last accessed Nov. 10, 2025).

[3] Id.

[4] Id.

[5] See Magdalena Petrova, Big Tech AI Underwater Cables, CNBC (Nov. 8, 2025), https://www.cnbc.com/2025/11/08/big-tech-ai-underwater-cables.html (last accessed Nov. 10, 2025).

[6] See TeleGeography, Submarine Cable Frequently Asked Questions (last accessed Nov. 10, 2025), https://www2.telegeography.com/submarine-cable-faqs-frequently-asked-questions.

[7] See Jillian Kay Melchior, On Patrol in the Baltic for Russian Saboteurs: International Law Makes It Harder for the Estonian Navy to Protect Critical Undersea Infrastructure, Wall St. J. (Mar. 4, 2025), https://www.wsj.com/opinion/on-patrol-in-the-baltic-for-russian-saboteurs-international-law-estonia-russia-china-critical-infrastructure-7c4fd9a5 (last accessed Nov. 10, 2025).

[8] Id.

[9] See Wilson Center, Mapping Undersea Infrastructure Attacks in the Baltic Sea, The Wilson Center (last accessed Nov. 10, 2025), https://www.wilsoncenter.org/article/mapping-undersea-infrastructure-attacks-baltic-sea.

[10] See Yleisradio Oy, Finnish Court: We Have No Jurisdiction in Eagle S Case, YLE NEWS (Oct. 3, 2025), https://www.yle.fi/a/74-20186464 (last accessed Nov. 10, 2025).

[11] See Wilson Center, Mapping Undersea Infrastructure Attacks.

[12] See The Maritime Executive, “Russian Dark Fleet Looks for Further Flags of Convenience,” THE MARITIME EXECUTIVE (Nov. 8, 2025), https://www.maritime-executive.com/article/russian-dark-fleet-looks-for-further-flags-of-convenience (last accessed Dec. 9, 2025).

[13] See Yle News, Finnish Court: We Have No Jurisdiction in Eagle S Case, supra note 10.

[14] See Amy Paik & Jennifer Counter, International Law Doesn’t Adequately Protect Undersea Cables. That Must Change, Atlantic Council — Hybrid Conflict Project (Jan. 25, 2024), https://www.atlanticcouncil.org/content-series/hybrid-warfare-project/international-law-doesnt-adequately-protect-undersea-cables-that-must-change/ (last accessed  Nov. 10, 2025).

[15] Id.

[16] See Paik & Counter, supra note 14; Jill Gallagher & Nicole Carter, Protecting Underseas Cables, Brookings Institution (accessed Nov. 10, 2025), https://www.brookings.edu/articles/protecting-underseas-cables/; Jill Goldenziel, Law Doesn’t Protect Undersea Cables. Russia and China Know It., Forbes (Feb. 13, 2025), https://www.forbes.com/sites/jillgoldenziel/2025/02/13/law-doesnt-protect-undersea-cables-russia-and-china-know-it/ (last accessed Nov. 10, 2025).

[17] See Convention for the Protection of Submarine Telegraph Cables, Mar. 14, 1884, 24 Stat. 989, T.S. No. 380, art. II.

[18] Id. at art. X.

[19] See National Oceanic and Atmospheric Administration (NOAA), Submarine Cables: International Framework (Apr. 15, 2024), https://www.noaa.gov/general-counsel/gc-international-section/submarine-cables-international-framework (last accessed Nov. 10, 2025).

[20] See United Nations Convention on the Law of the Sea, Dec. 10, 1982, 1833 U.N.T.S. 397, arts. 2–3.

[21] Id. at art. 56.

[22] See Gallagher & Carter, Protecting Underseas Cables, supra note 16.

[23] See Jill Goldenziel, Law Can’t Stop Submarine Cable Sabotage. Russia And China Know It., Forbes (Feb. 13, 2025), https://www.forbes.com/sites/jillgoldenziel/2025/02/13/law-doesn’t-protect-undersea-cables-russia-and-china-know-it/ (last accessed Nov. 10, 2025).

[24] Id.

[25] Id.

[26] Id.

[27] See CNBC, Big Tech AI Underwater Cables, supra note 5.

[28] See Jillian Kay Melchior, On Patrol in the Baltic for Russian Saboteurs: International Law Makes It Harder for the Estonian Navy to Protect Critical Undersea Infrastructure, Wall St. J. (Mar. 4, 2025), https://www.wsj.com/opinion/on-patrol-in-the-baltic-for-russian-saboteurs-international-law-estonia-russia-china-critical-infrastructure-7c4fd9a5 (last accessed Nov. 10, 2025).

[29] See Paik & Counter, International Law Doesn’t Adequately Protect Undersea Cables, supra note 14.

[30] Id.

[31] See Gallagher & Carter, Protecting Underseas Cables, supra note 16.

[32] Id.

[33] See Alexander Lott, Unconventional Legal Approaches to Protecting Underwater Infrastructure, Hague Ctr. for Strategic Studies (Mar. 2025), at 4, https://hcss.nl/wp-content/uploads/2025/03/Unconventional-Legal-Approaches-to-Protecting-Underwater-Infrastructure-HCSS-2025-1.pdf (last accessed Nov. 10, 2025).

[34] Id. at 6.

[35] Id.

This is a student blog post and in no way represents the views of the Fordham International Law Journal.