1. International law and the protection some critical infrastructures
In UNCLOS, the protection of both installations and cables can be attached to different maritime zones and different types of states.
For installations in general, first, in maritime zones within territorial sovereignty, Article 19.2(k) stipulates that any act aimed at interfering with coastal states’ facilities or installations can be identified as detrimental to coastal states’ security, hence not constituting an “innocent passage”
[1]. Therefore, coastal states can implements law to protect their installations in these maritime zones, according to Article 21.1(b)
[2] or take necessary measures to prevent passages that are not innocent, according to Article 25.1
[3]. Second, in the exclusive economic zone (EEZ), coastal states have exclusive jurisdiction regarding the safety of installations, and can create “reasonable safety zones” (not exceeding 500 meters) around installations, which are respected by all vessels, according to Article 60
[4].
For submarine cables, first, in maritime zones within territorial sovereignty, coastal states have the right to enact regulations to protect cables, including the right to regulate innocent passage, similar to installations mentioned above. Additionally, archipelagic states should allow the maintenance (which can aid protection) of cables passing through their archipelagic waters but laid by other states, according to Article 51.2.
[5] Second, in the EEZ, cable protection is not a legal obligation of states, but states laying cables in another state's EEZ shall comply with the laws and regulations adopted by the coastal state (including regulations aimed at protecting coastal states’ infrastructure). Article 58 says that all states also enjoy the freedoms associated with the operation of cables, which can include cable protection
[6]. Third, in the continental shelf, coastal states may not impede the maintenance of cables when conducting exploration.
[7] Fourth, in the high seas, states shall have “due regard” to cables already in position and avoid prejudicing possibilities of repairing existing cables or pipelines.
[8] Article 113 requires states to adopt laws and regulations to regulate the breaking or injury of submarine cables.
Besides UNCLOS, other documents also provide content on protection of critical infrastructure, specifically SUA and the 1884 Cable Convention.
For fixed platforms (including installations), the 1988 SUA Protocol sets forth what actions can be considered an “offence” in installations in Article 2
[9], including taking control over installations by force, conducting violence on those onboard such installations, or wrecking damage on such platforms, etc. Therefore, SUA Protocol stipulates that each state party will take necessary measures to establish jurisdiction over such offences, according to Article 3.1
[10], among others. The 2005 SUA Protocol provides amendments to the 1988 version, expanding the definition of “offence”, covering also the usage of explosive/radioactive material or discharges on installations, etc.
[11]
For submarine cables, the 1884 Paris Convention
[12] also defines what can be considered an “offence” to cables outside the territorial waters of states in its Article 2, which is the breaking or injury of a submarine cable, either willfully or with culpable negligence... To prevent such offences, the Convention puts forward multiple solutions, such as asking parties to use proper safety measures on granting a concession for landing cables in Article 3, asking cable’s owner to bear the cost if causing damage to another cable in Article 4, asking vessels to avoid collisions or keep fishing nets at safe distance from cable-repairing ships in Article 5, etc. Moreover, the Paris Convention also allows parties to pursue prosecutions in case of violations
[13].
2. Critical assessment of the international law framework
The above-mentioned documents have proven useful for critical infrastructure protection, especially cables, in two main ways.
First, they establish an expansive foundation for specific actions to base on. UNCLOS is considered the “constitution of the ocean” with 170 parties, ensuring a wide range of compliance. Even some non-UNCLOS parties, such as the United States, have affirmed that they follow UNCLOS in spirit
[14]. Therefore, in theory, the content of critical infrastructure protection can be upheld to a great extent. Regarding the 1884 Paris Convention, numerous scholars have argued that other legal documents, such as the 1884 Paris Convention, have become part of customary international law on submarine cable, citing it as the only sole international convention on this subject
[15].
Additionally, the content of the above-mentioned legal documents can be adopted into various national instruments. For example, Vietnam has taken inspiration from UNCLOS to shape multiple regulations aiming at submarine cable protection. Vietnam’s 2012 Law of the Sea declares that countries exercising the right of innocent passage within Vietnam's territorial waters are obligated to ensure the protection of submarine cables
[16], in line with UNCLOS’s Article 21 mentioned above. The Law also emphasizes that Vietnam will prioritize international law (including UNCLOS) in case of any difference
[17]. Vietnamese Prime Minister’s Directive No. 30/2007/CT-TTg
[18] mandates that the Border Guard, Navy and Vietnam Coast Guard (all under the Ministry of National Defense) are to ensure the security of telecommunication submarine cables inside maritime zones of sovereignty, in accordance with UNCLOS. Vietnamese Government’s Decree No. 162/2013/ND-CP
[19] and No. 174/2013/ND-CP
[20] also stipulate the penalties for drilling or cutting or performing any acts aimed to adversely affect normal operations of submarine cables and pipelines legally installed within the territorial waters, islands and continental shelf of Vietnam. Another example, Austria has been said to take inspiration from the 1884 Paris Convention to design its own penal provisions for submarine cable protection in 1888
[21].
Second, the documents on the protection of installations and submarine cables have also facilitated practical and technical coordination in real life. For example, Australia
[22] and New Zealand
[23] have introduced their own cable protection zones to prevent fishing or other activities that could cause damage to cables in the areas the cables pass through. Those zones are also consistent with UNCLOS
[24]. Moreover, UNCLOS also facilitates other activities that can indirectly enhance cable protection. In 2019, the ASEAN introduced its Guidelines for Strengthening Resilience and Repair of Submarine Cables, aiming to simplify the processes for obtaining permits for cable repair across Southeast Asia in line with UNCLOS
[25].
However, the positive impacts are not absolute as limits remain, regarding international law’s general problems of scope and compliance, as well as the implication of securitization and big powers’ competition trends.
The first problem is about international law’s coverage. Actor wise, UNCLOS grant all states the right to repair cables but in practice, cables are usually repaired by private companies
[26], who might not see eye to eye. For instance, when the U.S. and Japan introduced efforts to block engagement with Chinese cable operators for security reasons, some private cable industries have reportedly expressed disagreement for fear of losing further commercial benefits
[27]. In addition, many submarine cables are transnational, running across different maritime zones of different coastal states
[28], which might require extra international coordination and hinder the protection duty on the ground. Cable repair ships can also be foreign, thereby reducing the authorities of the states with the cables or coastal states. For example, when Vietnam’s Asia Pacific Gateway (APG) cable was disrupted in 2023 (on the branch S6 going to Hong Kong), the original repair plan was postponed partly due to the fact that the cable routes and repair ships all belonged to different operators in different countries and territories
[29].
Referent object wise, this essay only focuses on fixed platforms and submarine cables, but the problem lies in the lack of a universal definition of “critical infrastructure” in international law itself, consequently leading to a lack of universal protection. A survey by the German Council on Foreign Relations has concluded that among 194 actors (193 UN members and Taiwan), 94 have not defined this concept
[30]. For example, Vietnam’s Ministry of Construction has introduced Circular No. 06/2021/TT-BXD, which classifies multinational telecommunications lines as the construction of highest level of importance
[31], but the country has not defined which infrastructure it considers critical. For the actors who have done so, there are still 5% who do not consider information and communications technology, including submarine cables, as critical
[32]. The equivalent number for public services, including installations, is more than 10%
[33].
The second problem is about compliance. Compliance is a general issue in international law and even more prominent when it comes to infrastructure protection. For example, with UNCLOS and submarine cable, submarine cable offences are difficult to be prosecuted. Coastal states have only limited jurisdiction in the areas beyond territorial sovereignty, where breakages usually happen. The flag states can exercise that authority but are usually reluctant to do so
[34]. Some has pointed to ICPC as an organization to help enforce UNCLOS and protection of cables, but ICPC only provides guidances, best practices and suggestions
[35], not able to ensure compliance. Some have said that the 1884 Paris Convention applies to all maritime areas beyond territorial waters, but there are only 36 parties to the Convention.
Moreover, not all states subscribe to these above mentioned legal documents, making universal compliance not feasible. UNCLOS has 170 members, but key maritime states like the U.S. have not ratified the document
[36] (despite its public statements in support of UNCLOS). For the 2005 SUA Protocol, there are only over 40 parties
[37]. For the 1884 Paris Convention, the number is 36
[38], as mentioned previously.
Besides, states sometimes introduce national laws contradicting the international law documents they are parties to. With submarine cables, one study estimates that 80% maritime states, including such as Canada, China, Russia, Japan and the U.S., etc. have enacted the so-called “cabotage” laws. These laws can limit the cable repairing activities of foreign vessels in coastal states’ EEZ
[39], violating the freedoms associated with cable operation enshrined in UNCLOS. The vessels might then need to seek permission from coastal states, subsequently affecting the protection of cables. For example, Malaysia's “cabotage” law, which goes back to the 1980s and was only removed in 2024
[40], has been said to delay the cable repair process
[41].
The third problem is related to emerging geopolitical trends, including increasing securitization of infrastructure and competition in the maritime domain. Destroying critical infrastructure, such as submarine cables, has been labeled as a part of the “gray zone” or mixed warfare tactics
[42]. The cases of cable disruptions near Yemen during the Red Sea crisis
[43], in Baltic Sea
[44] or around Taiwan
[45], etc. can be evidence of sabotage for political purposes. Since the disruptors might be non-state, it is hard to attribute responsibility for those cases to not be repeated in the future.
Big powers’ competition also presents a new challenge for cable protection. In the South China Sea, China has been allegedly tightening licensing for international cable projects as a way to reinforce its authority and the “nine-dash line” claim
[46]. The U.S. has been reportedly making efforts to “disconnect” its cable network from China’s by promoting its own “Clean Network” initiative
[47] or intervening to outbid China’s operators in cable projects like SeaMeWe-6
[48]. As the submarine cable systems in the region become increasingly fragmented, the pressure to “take side” for smaller countries also increases, especially when they need foreign partners for cable repair and cable resilience improvement (via diversification of cable networks). For example, Vietnam may encounter difficulties in increasing its cable resilience as its SJC2 and Asia Direct Cable (ADC) routes, supposed to finish years ago, were delayed because of a lengthy permission seeking process from China. U.S. companies have diverted its route planning from the South China Sea, notably the Apricot and Bifrost projects
[49], potentially leaving Vietnam in a more vulnerable position.
All in all, installations and submarine cables are generally viewed as critical infrastructure, which are the subject of protection under various tools in international law, including the 1982 UNCLOS, 1884 Paris Convention, the 1988 SUA Protocol and the 2005 SUA Protocol. International law defines what actions can constitute an “offence” to the two types of critical infrastructure, as well as what parties can do to protect them, subsequently laying the legal foundation for further measures, such as crafting national/domestic regulations or designing technical cooperation plans. However, international law is not perfect, as there is no absolute compliance and coverage. The fact that critical infrastructure has not been universally defined and increasingly become the battleground or the tool of geopolitical competition further complicates international law’s problems.
Do Manh Hoang
South China Sea Institute, Diplomatic Academy of Vietnam
The views expressed in this article are solely of the author
[10] Protocol for the Suppression of Unlawful Acts Against the Safety of Fixed Platforms Located on the Continental Shelf Art 3(1).
[11] Protocol of 2005 to the Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation (opened for signature 14 October 2005, entered into force 28 July 2010) 2583 UNTS 114, arts 2bis, 2ter.
[12] International Convention for the Protection of Submarine Telegraph Cables, signed 14 March 1884, 24 Stat 989, TS 380 (entered into force 1 May 1888).
[13] International Convention for the Protection of Submarine Telegraph Cables Art 9.
[16] Vietnam,
Law on the Sea No. 82/2012/QH13, enacted 21 June 2012.
[19] Decree No. 162/2013/ND-CP, Government of the Socialist Republic of Vietnam, 12 November 2013
[20] Decree No. 174/2013/ND-CP, Government of the Socialist Republic of Vietnam, 13 November 2013
[21] Jason Halog, Paul Margat and Michael Stadermann, ‘Submarine Infrastructures and the International Legal Framework’ (2024)
Transactions on Maritime Science 13(1) 1-16, 9
https://hrcak.srce.hr/file/457744 [31] Vietnam Ministry of Construction,
Circular No. 06/2021/TT-BXD: Classification of Constructions and Guidelines for Application in Management of Construction Investment Activities (enacted 30 June 2021)
[32] Weber, ‘Mapping the World’s Critical Infrastructure Sectors’.
[34] Jason Halog, ‘Submarine Infrastructures…’ 7
