Law enforcement issues in the disputed maritime areas: apples and pears for the coastal states

A delimited maritime border is an essential requirement for creating a secure and stable environment that facilitates further development. However, standing hostilities and competing interests among neighbouring states have made delimitation agreements difficult; consequently, critical maritime areas remain undefined, leading to disputes. The present study employs qualitative legal analysis and comparative case study methodology, drawing on primary sources including UNCLOS provisions, bilateral agreements, arbitral decisions, official state documents, and empirical evidence of state practice from 1994 to 2025. Using the East and South China Sea disputes as case studies, this research examines the complexities of law enforcement in contested maritime zones where overlapping claims create jurisdictional challenges. The study also highlights the probable consequences of violating Articles 74(3) and 83(3) of UNCLOS and how this impacts the States’ practices in the disputed areas. Through detailed analysis of these two critical Asian maritime disputes, the study demonstrates how the overlapping maritime claims result in outstanding diplomatic business for the states concerned, which gives rise to tension in inter-state relations or even disputes; therefore, the rules of international law should provide clear guidance for the conduct of the coastal states during the period while overlapping claims remain undelimited.

1 Introduction

States that claim maritime zones are exposed to the continuous threats of unlawful activities in their waters, including conflicts of interest and claims. These may include modern versions of prehistoric activities, such as illegal fishing and piracy (Chang and Khan, 2021), as well as the cultured operations of global criminal networks involved in biosecurity incidents, marine pollution, wildlife or human trafficking, and the use of drugs. The nature and extent of threats will vary from region to region, and the degree to which a state is exposed to them will depend on the size and characteristics of its maritime zones, as well as its capacity to identify and respond to specific and imminent security challenges. The extension of maritime jurisdiction has resulted in an intensification of human activities far off shore, such as fishing and hydrocarbon exploration, coupled with an ever-increasing volume of international shipping, which all lead to more opportunities for unlawful activities. An essential strategy for States to increase their ability to deter illegal activity in their maritime zones is to cooperate with other States in potentially all aspects of law enforcement, from intelligence gathering and security patrols through to arrest and prosecution activities.

There are two general scenarios in which coastal states might be expected to benefit from a high level of bilateral or multilateral maritime security cooperation. The first involves efforts by law enforcement concerning the conduct aboard a foreign vessel that has sought to avoid arrest by fleeing into the waters of another state or onto the high seas. This would require worldwide cooperation since jurisdictional rights and protections of neighbouring States must be observed. The second circumstance is when a coastal State has inadequate enforcement and surveillance resources to police its maritime zone, leading to the need to share resources with its neighbours. The advantages of such cooperation with neighbouring States in surveillance and enforcement operations include reduced cost of law enforcement, deterrence, and more prosecutions of illegal activities. These translate to greater effectiveness of at-sea operations, for instance, the ability to enhance coordination of sea, air, and land-based enforcement procedures (Leary et al., 2020).

The fundamental principle, according to which no state can exercise its territorial sovereignty on the high seas, seems to be a central component in the consecutive organisations of international law of the offshore regime. A maritime law report in 1956, which also served as the basis for the deliberations of the states at the First United Nations (UN) Convention on the Law of the Sea (UNCLOS) and the International Law Commission (ILC) commented that “the principle generally accepted in international law that the high-seas are open to all nations governs the whole regulation of the subject” and “that no state may subject any part of the high seas to its sovereignty, or exercise jurisdiction over any stretch of water” (United Nations, 1956). The unoccupied status of the high seas was strengthened by maintaining the wording virtually identical to Article 2 of the Convention on the High Seas (United Nations, n.d.-b) and Article 89 of the UNCLOS, according to which “no state may, rightly claim to subordinate part of the high seas to its sovereignty”. At present, Asian countries demonstrate the most imperative maritime disputes across the globe. It is important to note that while most Asian countries are parties to UNCLOS, some significant maritime powers, such as the United States, are not signatories to the Convention. However, non-signatory states may still employ UNCLOS dispute resolution procedures and principles if they have internalised certain UNCLOS practices as customary international law. This occurs when widespread state practice, combined with the opinio juris (the belief that such practice is legally required), elevates UNCLOS provisions to the status of customary international law, which binds all states regardless of treaty ratification. Although, the dispute settlement system has rarely been used in a few cases, despite the fact that most of the Asian countries are parties to UNCLOS (Song, 2023). Furthermore, the negotiations have yielded inadequate results in alleviating various tensions, raising questions about the UNCLOS’s dispute settlement system’s ability to play a productive role in settling maritime disputes (Nguyen, 2018).

The UNCLOS codified maritime regulatory and enforcement powers, as well as the limits to those powers. Enforcement power is dependent on any particular instance upon the jurisdiction. Jurisdiction is inherently technology-neutral; yet, UNCLOS was agreed upon in 1982 only after decades of international negotiations. The most intense negotiating period occurred during the 1970s (Warner and Kaye, 2016). However, that period represents an entirely different technological context from that of today. The application of maritime regulation and enforcement has consequently burgeoned. It has been agreed that coastal States should cooperate, accept, and allow other coastal States to exercise sovereignty over their territorial waters. However, overlapping in the sphere of maritime jurisdiction or disputes is unavoidable. The current study has focused on the notion that the disputed maritime areas raise various legal issues related to law enforcement during their execution. In addition to elucidating key terms, law enforcement and disputed maritime areas, critical legal issues, and states’ responsibilities in contested maritime areas, this study has also discussed the likely consequences of violating the relevant Articles of UNCLOS.

1.1 Research gap and contribution

While maritime disputes in the South China Sea and East China Sea have received extensive scholarly attention, existing research exhibits several significant gaps that this study addresses.

Gaps in Existing Scholarship—First, most existing studies examine either the South China Sea or the East China Sea in isolation, lacking systematic comparative analysis of law enforcement challenges across both disputes (e.g., Anderson and van Logchem, 2014; Carl, 2025; Patalano, 2014; Strating, 2021). This fragmented approach limits understanding of generalisable patterns in maritime law enforcement under conditions of overlapping claims. Second, the existing literature tends to focus predominantly on sovereignty disputes and maritime boundary delimitation (e.g., Gau, 2019; Hall, 2019), with insufficient attention to the practical law-enforcement challenges during the interim period before disputes are resolved. The gap between abstract legal principles and concrete enforcement practices remains underexplored.

Third, scholarship has inadequately examined the tension between UNCLOS Articles 74(3) and 83(3) obligations—requiring states to “make every effort to enter into provisional arrangements” and “not to jeopardise or hamper the reaching of the final agreement”—and actual state practice in disputed waters. While legal scholars have analysed these provisions theoretically (Anderson and van Logchem, 2014), there is insufficient empirical analysis of how states interpret and apply these obligations in the SCS and ECS contexts. Fourth, existing policy recommendations often lack empirical grounding in successful precedents from other regions. Studies frequently propose cooperation mechanisms without systematically examining analogous cases where states have successfully managed law enforcement in disputed maritime areas.

This Study’s Contribution—This research addresses these gaps through four principal contributions: First, it provides a systematic comparative analysis of law enforcement challenges in the SCS and ECS, identifying common patterns and context-specific factors that shape enforcement dynamics. Second, it conducts a detailed analysis of the gap between UNCLOS provisional arrangement obligations and actual state practice, examining how legal ambiguities create space for competing interpretations and what consequences result from failure to establish effective provisional arrangements. Third, it grounds policy recommendations in empirical precedents from successful regional maritime cooperation frameworks, including the Djibouti Code of Conduct, Mediterranean environmental agreements, and bilateral fisheries arrangements, providing evidence-based, practically feasible prescriptions. Fourth, it provides updated empirical analysis incorporating developments through 2025, including the Japan-China Maritime and Aerial Communication Mechanism (2023), recent ASEAN-China Code of Conduct negotiations, and evolving bilateral arrangements, ensuring the research reflects current realities and provides relevant insights for contemporary policy debates.

1.2 Methodological approach

This study employs qualitative legal analysis and comparative case study methodology. The analysis draws on multiple data sources: (1) primary legal sources including UNCLOS, bilateral fisheries agreements (China-Japan 1997, China-South Korea 1998), joint development agreements (2008 Japan-China Understanding), and regional frameworks (ASEAN-China Declaration 2002); (2) case law including the South China Sea Arbitration (PCA Case No. 2013-19, 2016); (3) official state documents from foreign and defence ministries of claimant states; and (4) state practice evidence from maritime incident reports and diplomatic communications (2023-2025).

The South China Sea and East China Sea were selected based on: (1) legal similarity—both involve overlapping claims governed by UNCLOS Articles 74(3) and 83(3); (2) structural variation—the cases differ in number of claimants and geographic configuration, enabling comparative analysis; (3) contemporary significance—both represent active disputes with recent developments in cooperative mechanisms; and (4) data availability—sufficient public documentation exists for balanced analysis.

Correspondingly, the analytical approach proceeds through: (1) doctrinal legal analysis of UNCLOS provisions; (2) case study analysis examining legal positions, enforcement mechanisms, and cooperative frameworks; (3) comparative analysis identifying common patterns and variations; and (4) policy synthesis based on successful precedents from other regions.

The present study employs a qualitative approach to examine the states’ practices regarding law enforcement in the disputed maritime areas. After the introduction, Section Two presents a brief analysis of the key terms pertinent to the study and an overview of maritime boundaries and disputed areas, as well as law enforcement under international law. Section three provides an in-depth discussion and analysis of the rights and responsibilities of coastal states in disputed maritime areas, including sovereignty, sovereign rights, and jurisdiction. This section thoroughly discusses and analyses the critical issues concerning the disputed maritime areas among the coastal states. Additionally, it provides an analysis of the obligations these states are required to fulfil under Articles 74(3) and 83(3) of UNCLOS. The preceding section elaborates on two major and relevant case studies, the South China Sea and East China Sea Disputes, along with the comparative analysis. Sections five and six conclude the discussion and analysis with precise concluding remarks and appropriate recommendations on how policymakers and state actors should address these challenges.

2 Brief analysis of the pertinent key terms

2.1 21^st century and the challenges in law enforcement

The challenges law enforcement faces in the 21^st century are incredibly complicated and are continually evolving. Some of them are new twists on old problems; others are new and challenging, which the present world could not have imagined or even prepared for 20 years ago (Thompson and Canterbury, 2017). As a result, it is challenging to anticipate some rapid changes that will test one’s ability to perform their job and protect public security.

Law enforcement faces various challenges, including vulnerabilities in criminal justice, inter-agency cooperation, restoring public trust, social media, unmanned aerial vehicles (UAVs), encryption of the communication devices, equipment and facilities, opioid epidemic, human trafficking, terrorism, mental health, adequate funds and grants, and conflicts between international regulations and national interests as well as domestic laws (Jun, 2012; Thompson and Canterbury, 2017). It necessitates the coastal states to take appropriate measures to address these issues and avoid unnecessary use of force in the disputed maritime areas (Tondini, 2017). To this end, it should be ensured whether the law enforcement measures undertaken by the coastal states and regional and international organisations have a legal basis in international law and the UNCLOS or otherwise.

2.2 The UNCLOS and maritime areas

It is essential to understand first the legal meaning of the ‘maritime areas’ before defining and digging further into the term ‘disputed maritime areas’ and pertinent law enforcement issues. The UNCLOS approach is (although with a few exceptions) essentially a ‘zonal’ one. It usually sets out rules of the law of the sea in ‘chapters’, which are also referred to as ‘sections’ or ‘parts’, which relate to the various sea areas. These sea areas designated by UNCLOS include: (a) internal waters; these are stated in numerous articles (Treves, 2015); however, their regime has not been completely expounded, perhaps due to the reason that it has been assumed that it is not fully international law, b) the territorial sea, (c) the contiguous zones, (d) the archipelago waters, (e) the continental shelf, (f) the exclusive economic zone (EEZ), (g) the international seabed area, (h) the high-seas, and (i) an area the boundaries of which accord with the adjacent area in which states may submit the deletion of archaeological and historical objects (sometimes referred to as an archaeological area) for approval (Treves, 2015). It is imperative to differentiate the sea areas of the coastal states, which have a ‘privileged position’ over other sea areas and states, and where all the coastal states enjoy ‘equal rights’; the international seabed area and the high-seas belong to the second category, whereas all the above-listed areas belong to the first category.

2.3 Maritime boundaries and disputed maritime areas

Maritime boundaries are conceptual divisions of the earth’s water surface consistent with geopolitical or physiographic criteria. Intrinsically, it generally delimits zones with exclusive national rights to biological and mineral resources (General Information at VLIZ Maritime Boundaries Geodatabase, n.d.), including features, borders, and marine zones (Applying Geoscience to Australia’s Most Important Challenges: Maritime Boundary Definitions, n.d.). In general, a maritime boundary is defined as a certain distance from the coast of one jurisdiction to another. Though in some states, the maritime border refers to the boundary of a maritime nation (Maritime Boundaries, n.d), which UNCLOS recognises, maritime borders are generally used to recognise the edges or limits of the high seas (Baser and Biyik, 2016).

Disputes regarding controversial sea areas differ from those on land, as sea areas are a relatively new concept in international law. While states’ claims to a territorial sea go back to the first period of maritime law (15^th to 16^th centuries), most of the sea areas - namely the EEZs and continental shelves - date from the second half of the 20^th century; a process of expanding the rights of coastal states as organised and codified by the UNCLOS from 1958 and 1973-1982 (Milano and Papanicolopulu, 2011). In almost all disputed maritime borders, the parties are encouraged to define a formerly undefined area where their claims overlap,¹ and maritime border disputes could be considered, the rule at sea, since most of the maritime borders are still to be resolved.

The general disputes over maritime areas can be further divided into two types of distinguished disputes. The first kind relates exclusively to the demarcation of the border between the sea areas claimed by the surrounding countries. The second category of disputes apprehends the right to sea zones. Disputes over the rights of islets, rocks, and islands to the continental shelf and EEZ are of particular importance given the demands of Article 121 (3) of UNCLOS, sometimes accompanied by a dispute over the title of the island (Prescott and Schofield, 2005).

UNCLOS provides an opportunity for all island states to regulate maritime borders without resorting to court proceedings. There are two approaches available for this purpose: the first is for states to agree to draw an ‘equidistant line’ between them, as is the case with the 20-mile limit across the Dover Strait between France and England. The second approach is an equidistant line, which is used to accomplish a fair result. For instance, the 2010 maritime border agreement between Russia and Norway on the Arctic Ocean, in which both sides made noteworthy concessions, allowing these two states to further the exploration process for gas and oil resources (Freestone, 2014). However, recourse to the courts, in some cases, is inevitable. In these cases, some unique techniques such as ‘a check of disproportionality’ are applied. Where the particular proportion of countries in the areas in question are clearly disproportionate to their coasts, as was the case in the dispute between Canada and the United States (US) in the Gulf of Maine, where the World Court resolved the issue (Newman, n.d), this very situation comes up with a ‘disputed maritime area’. The Disputed Maritime Areas may also be known as ‘Contested Maritime Areas’, ‘Undelimited Maritime Areas’, and ‘Grey Areas’.

UNCLOS does not provide the exact definition of the disputed maritime areas. However, UNCLOS articles on the delimitation of EEZ and the continental shelf contain two identical provisions, Article 74(3) and Article 83(3), that provide for this situation (Burke et al., 2016). These provisions contain two obligations, which the parties to the dispute will ‘meet their best’ until an agreement is reached on the demarcation in a spirit of cooperation and understanding; make provisional agreements of a practical nature and do not hinder or jeopardise the conclusion of the final agreement during this transition period (United Nations, 1982a).

Many of the off-shore islands’ disputes affect the above two claiming countries: for instance, China, Taiwan, Brunei, Malaysia, the Philippines, and Vietnam come up with their claims to some or all of the Spratly Archipelago islands; where China, Japan and Taiwan claim the Senkaku Islands; and China, Vietnam and Taiwan claim the Parcells archipelago Islands (Fravel, 2014). If all other things are the same, disputes with more than two contestant states are even more difficult to resolve. Several factors indicate that competition for these disputes could intensify and become acute in the future. All states, particularly developing countries in Asia, are increasingly dependent on maritime resources, including fisheries and energy, and energy problems are intensifying the significance of such disputes, even with the unknown or unexplored underlying reserves. The islands’ sovereignty is a symbol that appeals to the national public, possibly due to the fact that only a few of these elements are engaged. The U.S. is not itself a direct claimant but continues to be sensitive to the possible threats to the freedom of navigation in other countries’ maritime areas, as it underpins the US Navy’s ability to operate freely in the world’s oceans (Fravel, 2014).

2.4 Maritime disputes and international law

A territorial dispute (including land and maritime areas) is a disagreement over the control or possession of sea or land areas between two or more countries. In any case, the use of force by any state is not supported by international law to annexe the territorial land and water of another state. Article 2 of the UN Charter says, “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or any other manner inconsistent with the purposes of the UN” (United Nations, n.d.-a).

Historically, the great powers have had access to the ocean (Khan and Chang, 2025), i.e., the U.S, Britain, Japan, Spain, Holland, Portugal, Germany and France. States that are expected to be major powers in the 21^st century also include some developing countries, such as Brazil, China, and India (Hong, 2015). International law is crucial for addressing the diverse challenges posed by the world’s oceans (Khan and Chang, 2025). UNCLOS 1982 defines three different areas: international waters (high seas), territorial waters, and EEZs. Territorial waters are those that are under an island state’s sovereign control and are legally recognised twelve nautical miles (nm) measured from baselines determined in accordance with UNCLOS. Article 3 of UNCLOS establishes that every State has the right to establish the breadth of its territorial sea up to this 12 nautical mile limit, measured from baselines determined in accordance with the Convention. It is noteworthy that the ships of all states enjoy innocent passage from this area; however, it comes under the exclusive control of the adjoining states. The EEZ is located beyond twelve nautical miles and stretches up to 200 nautical miles into the sea. Within an EEZ, the coastal states enjoy the exclusive rights to exploit and use available marine resources, i.e., fishing, seabed exploitation, as well as natural gas and oil exploration (Li and Khan, 2024). The global community continues to enjoy the freedom and rights to navigate and fly over the EEZ, as well as the ability to use the oceans without resource extraction, including the laying of submarine telecommunications cables (Reveron, 2010). Freedom of navigation, as defined under UNCLOS, encompasses the rights of all states to navigate, overfly, and engage in other internationally lawful uses of the sea in areas beyond territorial waters. Specifically, Article 87 of UNCLOS establishes freedom of navigation as one of the fundamental freedoms of the high seas, while Article 58 extends these navigation rights to the EEZ, subject to the due regard for the rights and duties of the coastal state. This principle ensures that commercial shipping, naval vessels, and aircraft can traverse international waters and EEZs without requiring permission from the coastal state, provided they do not interfere with the coastal state’s sovereign rights over resources or other jurisdictional matters. Outside the 200 nm, there are high seas where all countries, including both coastal and non-coastal states, enjoy the freedom of the seas and have equal access to engage in various activities.

Besides the issues mentioned above, maritime disputes are common, even among states with clearly defined borders; some coastal states compete for inhabited as well as uninhabited islands (Liao et al., 2023). For instance, Argentina and the United Kingdom waged war over the Falkland Islands in the South Atlantic in 1982, which are located 700 miles from Antarctica and 300 miles from South America (Livingstone, 2018). The disputes stem from competing claims about what the Argentinians call the Malvinas and the British call the Falkland Islands. Both claims are rooted in centuries-old colonial claims by the Spanish and British (which, however, are governed from Buenos Aires, Argentina).

3 Discussion and analysis

3.1 Rights and responsibilities of a coastal state in the contested maritime areas

3.1.1 Rights of the coastal states in maritime areas; sovereignty, sovereign rights, and jurisdiction

The various rights of the coastal states under UNCLOS consist of ‘sovereignty’ over the territorial sea and archipelago waters; in ‘sovereign rights’ with respect to economic activities and resources in the EEZ, and continental shelf, whereas, in ‘jurisdiction’ concerning artificial islands, fortification of the marine environment in the EEZ, facilities and structures, and marine scientific research (United Nations, 1982b). The rights of coastal states in adjacent zones are specified as control rights, and the rights of the archaeological zones as the right to authorise the elimination of certain goods. Therefore, it can be said that ‘Sovereignty’, ‘sovereign rights’ and ‘jurisdiction’ are exclusive rights, i.e., certain activities are carried out to the elimination of others (Treves, 2015). These dramatically oppose the freedoms of the other states to enjoy the free passage as recognised by oceanic countries, which have the right to demand that the other coastal states not to interfere.

The terminologies adopted by UNCLOS appear to indicate that the rights of oceanic states, as identified by the ‘sovereignty’, are exclusive and more intense than the ‘sovereign rights’ and that such rights are relatively exclusive and more intense than the ‘jurisdiction’ (Treves, 2015). Despite the fact that these may be correct and just, one should not place too much emphasis on finding the difference between these concepts. The rights that they imply must be determined by the meaning of the terms as specified in the Articles of the UNCLOS (for example, those in part V and part XIII related to the EEZ, scientific research, and fishing), and general international law recognises the oceanic countries.

3.1.2 Responsibilities of the states in disputed maritime areas

A state unquestionably exercises its sovereignty over its territorial sea and land, as well as its sovereign rights and responsibilities in adjacent sea areas in accordance with the generally accepted principles and standards of international laws (Milano and Papanicolopulu, 2011). Sovereignty implies the ability to trade across a sea area or zone and exclude other states from trading. Sovereign rights at sea imply exclusivity in the exploitation as well as the exploration of mineral resources, averting other coastal states from participating in these activities (but not in the maritime area in which these activities occur). If a coastal state acts in the territorial sea or on the territory of other states without due authorisation, it violates its territorial sovereignty. Likewise, a state violates its rights if it performs activities related to another state’s resources or other activities that fall within its jurisdiction or exclusive rights in its sea areas. This necessarily implies the international responsibility of the former and the duty to make full compensation for the damage caused.

3.2 Critical legal issues involved in disputed maritime areas

3.2.1 Sovereignty issues over ownership and boundary delimitation of islands

In the wake and creation of the 1982 UNCLOS, which has codified what rights and responsibilities coastal states have in claims up to 200 nm of the EEZ and a further extension, up to 350 nm of their claims to the continental shelf from the baselines, several states have pursued their maritime jurisdiction extension beyond their territorial (traditional 3 nm of) waters (Kim, 2008). Geographically, for instance, East Asian countries are located across from and next to each other across enclosed or semi-enclosed seas that are less than 400 nautical miles wide.² This was inevitable, leading to overlapping claims of maritime boundaries and resources. Essentially, the maritime boundary and territorial dispute can be boiled down to the points given below: one is over the ownership of disputed islets, an issue of territorial sovereignty, and the other is the question of the delimitation of maritime boundaries drawn from the disputed islands or the baselines of mainland coasts, and hence the subsequent exploitation of resources within these extended maritime boundaries; it is, therefore, a combination of sovereignty and sovereign rights.

3.2.2 Issues concerning baselines

Nonetheless, the majority of these straight baseline claims are disputed on the grounds that they fail to meet the conditions of straight baselines as provided for under UNCLOS, and therefore, inherently, act as a dispute starting point regarding the delimitation of maritime boundaries in most cases. For China, the waters bound by the new straight baseline system illustrate a relationship with the land that is very loosely defined (Khan et al., 2024). They are designed, instead, to mimic the character of the high sea or territorial seas (United Nations, 1996). The coastline is markedly smooth from the Shandong Peninsula of the Chinese coast to the region of Shanghai, and no fringing islands bound it. There are numerous indentations, including this part of the coast, that would meet the condition to qualify for a juridical bay (US-State Department, 2020). Other states with coastal interests also claim that Bohai Bay—with an entrance 45 nm wide—and the barren islet of Dong-dao—located 69 nm off the coast—also do not meet the qualification for needing baselines under UNCLOS (US-State Department, 2020). For instance, South Korea has claimed that China’s use of a straight baseline is inapplicable to the criteria for establishing a straight baseline under UNCLOS and has rejected the legitimacy of Dong-dao Island as a base point (Kim, 2008).

3.2.3 Territorial waters and contiguous zones

Under UNCLOS, coastal states have adopted a territorial sea of 12 nautical miles, plus a contiguous zone of each, except in certain waters where claims overlap between states with adjacent or opposite coasts, or other factors, such as freedom of navigation and international relations (Kim, 2008). For example, the Chinese claim to territorial waters is tricky if considered in association with its straight baselines. For instance, in 1992, in the laws of the People’s Republic of China on the Territorial Waters and Their Contiguous Areas and 1998 on the Continental Shelf and the EEZ, with the declaration of straight baselines, EEZs, and continental shelves around those disputed islands, China claimed its sovereignty over islands in dispute: the Senkaku Islands (vs. Japan), the Paracel (vs. Vietnam), and the Spratly Islands (vs. Taiwan, the Philippines, Malaysia, Brunei, and Vietnam) (Kim, 2008). The Chinese Laws aroused some protests on the part of the claimants of the disputed islands, such as Vietnam, Malaysia and Japan. The Chinese laws also specify the right of pursuit by Chinese warships and aircraft against foreign warships in Chinese territorial waters without permission (Tian et al., 2023).³ These legal developments have safeguarded the maritime security of coastal states, providing them with a compelling reason to adopt this approach.

3.2.4 EEZs and continental shelves

In terms of the continental shelf delimitation and the EEZ, most of the states of the East Asian maritime boundaries are still officially undecided. North Korea and Russia declared their EEZs first in 1977 and 1984, respectively; however, China, Japan, and South Korea did not declare their EEZs until South Korea and Japan passed their EEZ laws in 1996, followed by China in 1998 (Kim, 2008). This was mainly because claims overlapped with regional maritime geography featuring seas of less than 400 nm in width and, further, due to territorial disputes between the countries over islands located in their claimed EEZs. Because of the active policies in seagoing as part of capacity building, these countries’ proclamation of EEZs came after most coastal states and seemed to be an exception.

The EEZ claims between China and Japan substantially overlap in the East China Sea, with coastlines that are near or face each other (Patalano, 2014). According to Article 74 of UNCLOS,⁴ the principles applied to the delimitation of maritime boundaries between states having coastlines that are near or face each other are as follows: Japan cites the principle of the median line, and China cites the principle of the natural prolongation of territory. It argues that its continental area lies within the continental shelf of the East China Sea, as the continental shelf has a depth of less than 100 meters and a slightly undulating slope that extends as far as the Okinawa Basin, where the hill reaches its deepest point and drops sharply from 2,717 meters.

For the provisional arrangement of the maritime boundary delimitation, Japan and China agreed, under a fisheries agreement signed in 1997, the establishment of a joint fishing area (Provisional Measures Zone) in the waters between latitude 30° 40´ N and latitude 27° N where their claims overlap, to EEZ areas extending 52 nm from each coastline, and for the exploitation of the marine mineral resources to be jointly managed under the China-Japan Joint Fisheries Committee (Xue, 2005).⁵

3.2.5 Territorial disputes or disputes concerning islands

Most notable is the conflicting claim over the disputed islands, which relates to sovereignty on the part of the disputants. It would not be far off the mark to say that most of the maritime disputes are deeply rooted in the ownership issues of the disputed islands, and without resolving the territorial disputes one way or another, settlement of the maritime disputes would be unattainable—or at least without finding a way around them. Similarly, there are interim measures in which coastal states are involved, such as fishery agreements, apart from the substantive issue of conflicting claims about maritime boundaries. For example, the Senkaku Islands are at the core of maritime disputes between Japan and China. The islets between Japan’s Ryukyu Island and Taiwan consist of three barren rocks and five uninhabited coral islands (Kim, 2008). The control of these islands is currently under Japan, although the Republic of China and Taiwan also claim the islands. It was in the 1990s that tensions increased between Japan and China over the islands when both countries declared their respective territorial waters and EEZ; they began including the Senkaku in their respective EEZ. According to China’s claim, there are two principles that justify its case: the principle of territorial cession and the historical title of the islands. On the other hand, Japan insists that the Senkaku Islands are an inherent part of Japanese territory, denying that there is a disagreement regarding the sovereignty of the islands, while also somehow lacking legitimacy in its claim (Su, 2005). The potential of an islet to generate an expansive maritime boundary is to be seen in connection with sovereignty claims; otherwise, it is of no focus in a dispute over disputed islets (Prescott and Schofield, 2005).

3.3 States’ obligations in disputed maritime areas under Articles 74(3) and 83(3) of UNCLOS

UNCLOS contains primary rules that specifically address situations in disputed sea areas, as outlined in Articles 74(3) and 83(3) of UNCLOS.⁶ These provisions, which are worded identically, reflect the peaceful settlement of disputes as well as the general principles of good faith and comprise two obligations: the obligation to make provisional agreements and the obligation not to impede or jeopardise the final settlement of the maritime border. These are more a commitment to behaviour than to result. These do not rely on the prior opening of negotiations concerning settling down the maritime border, even in the case of a maritime dispute (Nordquist Myron, 1993). To some extent, the obligation not to impede or jeopardise the final arrangement could be tentative with regard to delimitation negotiations in some cases.⁷ The same applies to provisional regulations that could bring the parties closer together and enable negotiations to resolve the demarcation dispute once and for all.

Articles 74(3) and 83(3) of the UNCLOS do not de jure restrict the powers of the coastal states in the disputed maritime areas, which have yet to be demarcated. These powers, therefore, remain those that are commonly assigned to the coastal states in accordance with the pertinent provisions of UNCLOS as well as customary international law. However, Articles 74(3) and 83(3) of the UNCLOS establish a second condition for the exercise of these rights in the disputed maritime areas, subject to the reasonableness of each claim. If a coastal state does not meet the requirements of Articles 74 (3) and 83 (3) of UNCLOS and still exercises a right granted under UNCLOS, it can assume its international responsibility. There are several obligations that the coastal states owe in cases where such claims overlap, as explained in the subsequent headings.

3.3.1 The obligation of the coastal states to make all efforts to enter into provisional arrangements

The first obligation under Articles 74(3) and 83(3) of the UNCLOS is positive. As a result, states involved in disputes over the disputed maritime areas seek to enter into provisional agreements to address the circumstances of contesting claims; this obliges the parties to negotiate positively and in good faith. As such, it does not require the parties to come up with an agreement or even to adopt a particular solution; nevertheless, it entails some action on their part, rather than just passive inaction. The Arbitration Tribunal of Guyana/Suriname highlights some active practices that can meet the requirements of Article 74 (3) and Article 83 (3) of UNCLOS: dynamically trying to take other parties to the table of negotiations;⁸ accept the other party’s invitation to negotiate;⁹ inform the other party officially and in detail of the proposed activities; request the other party for the cooperation in carrying out the proposed activities; offer to share the financial benefits of the activities in the contested areas; offer to share the results of exploration in the disputed area.¹⁰ It is also worth mentioning that the list of activities provided by the Court is not comprehensive; nonetheless, it is usually considered acceptable. Activities can be divided into two categories: those that must be carried out to meet the requirements of Article 74(3) and Article 83(3) of UNCLOS, and those that are not necessary but are clearly compatible with the obligations outlined in the above-mentioned provisions. The obligation to negotiate requires coastal states to enter into negotiations with other parties or, at the very least, agree to consider the invitation of other parties to discuss applications in a positive manner.¹¹

In conclusion, the obligation to make every effort to conclude provisional agreements is a legal requirement to actively attempt to initiate negotiations to address potential problems until the final delimitation dispute arises. This in no way implies an obligation to agree, even if the conclusion of provisional agreements undoubtedly requires compliance with this provision. The non-exhaustive list of activities provided in the Guyana/Suriname Award is a suitable guide for assessing the States’ behaviours. However, the behaviour of states should be assessed on a case-by-case basis, considering all elements of the cases and evaluating any act or inaction by the coastal states in the context of their overall behaviour since the commencement of the disputes.

3.3.2 The obligation not to hamper or jeopardise the final settlements

The second obligation, generally derived from Article 74(3) and Article 83(3) of the UNCLOS, is negative. According to this, a state involved in a disputed maritime area need not to act in a way that jeopardises or hampers the final settlement of the disputes. The primary difficulty in applying and interpreting these provisions arises from the need to strike and maintain an appropriate balance between two different and opposing considerations. On the one hand, it is necessary to avoid unilateral measures as far as possible, as they may exacerbate the dispute and endanger international security and peace.¹² On the other hand, not all such activities (unilateral) need to be paralysed until the border is finally settled.

A state’s exploration of resources could be considered a danger to the dispute by the other, especially if it is carried out without the former’s prior notice to the latter. Judges of international courts have not addressed the exploitation of renewable resources, such as living resources. In the latter circumstance, it is actually easier to argue that activities concerning the exploitation and exploration of mineral resources do not cause permanent harm and can even be carried out separately in the same area by both coastal states.¹³ Nevertheless, poor coordination or harmonisation in the exploration and exploitation of renewable (mineral) resources could conflict with the need to conserve such resources, as is required in Article 61 of the UNCLOS.¹⁴

3.3.3 Obligations of restraint and sovereignty disputes

The role of disputes related to territorial sovereignty or the status of maritime characteristics is significant in paragraph 3 of Article 74 of UNCLOS, particularly in the application of the obligation not to jeopardise or hinder the achievement of a final settlement in accordance with Articles 74(3) and 83. One of the main characteristics of the obligation not to jeopardise or hinder their existence, as revealed in the in-depth analysis of state practice, is that the most significant factor appears to be the tendency to work, since the provisions themselves do not set a geographical limit for the underlying obligation or hindrance to reaching the final agreement. The question arises as to whether a given test is justified, such as the one proposed by the Guyana v Suriname Tribunal, which states that the activity causes a physical change in the seabed.¹⁵ The obligation itself could affect the availability of countermeasures for the country concerned, although, in practice, states often respond to violations without exercising moderation.

Sovereignty dispute situations illustrate the complex relationship between the UNCLOS Articles 74(3) and 83(3) obligations and other international obligations that may exacerbate or mitigate disputes (Burke et al., 2016). In such situations, it is challenging to determine whether countries are fulfilling their UNCLOS obligations or, more broadly, self-regulation obligations related to the non-aggravation of existing disputes. In addition to the above obligations, states must also exercise some form of good-faith moderation. To this end, for example, interim fisheries agreements often require states not to apply their laws against ships of the other party. However, this could create tensions with commitments related to the management of these resources.

3.3.4 Consequences of the violations of Articles 74(3) and 83(3) of UNCLOS

The first consequence of violating Article 74, paragraph 3, and Article 83, paragraph 3, of the UNCLOS is the obligation to cease the illegal behaviour and provide reasonable guarantees and assurances against non-repetition.¹⁶ This obligation is particularly significant because states in disputed sea areas could face various violations of the obligations set out in Article 74 (3) and Article 83 (3) of the UNCLOS. The parties also remain obliged to continuously adhere to the requirements of such provisions; therefore, a coastal state must not withdraw definitively from the negotiations, even if the respect of its obligations by other states and the cessation of illegal behaviour could be a condition for its continuation. These obligations apply to the parties unless the dispute is resolved by agreement or by a binding decision.

A complex problem concerns the ability to take countermeasures to compel the other country to fulfil its obligations under Article 74(3) and Article 83(3) of the UNCLOS. Countermeasures are generally permitted, provided they are proportionate, balanced,¹⁷ and do not violate the obligations under the mandatory rules of international laws, including the obligation not to threaten or use violence.¹⁸

Exploitation activities may constitute a serious breach of the obligations set out in Article 74(3) and Article 83(3) of the UNCLOS and may impact the resumption of performance.¹⁹ In general, although the coastal states might argue that exploitation of mineral resources could be considered a proportionate and legitimate countermeasure under certain circumstances; the states should avoid these activities as these may easily be disproportionate and lead to an escalation of the dispute between the two states and to serious compromises to reach a final settlement. Secondly, some commentators have proposed that various measures concerning law enforcement can be seen as a legitimate countermeasure to violations of international law rules (Guilfoyle, 2007). In the disputed sea areas, however, law enforcement measures are fairly difficult to consider as countermeasures, as they are legal in most cases and, therefore, do not violate the guidelines of international laws. On the other hand, if they are carried out with more violence than legitimate or appropriate, and if they are carried out without proper respect for human rights, or if they comprise reprisals that violate humanitarian principles, they are, in any case, inadmissible.²⁰

4 Case studies

To illustrate the complexities of law enforcement in disputed maritime areas, this section examines two prominent case studies: the South China Sea dispute and the East China Sea dispute. These cases highlight the intricate interplay of legal, political, and economic factors that shape maritime conflicts and enforcement challenges in Asia.

4.1 South China Sea dispute

The South China Sea dispute over who owns what in the Spratly Islands and Paracel Islands, as well as where to conduct military training, issues that loom large again, has been dubbed one of Asia’s most dangerous hotspots for good reason. It has multiple claimants, with China, Vietnam, and the Philippines being historically the most active; Malaysia also holds claims, as does Brunei, according to Raymond and Welch (2022). The dispute is all the more significant given that it involves a strategically located area abundant with resources and crucial shipping lanes (as shown in Figure 1).

Figure 1

Figure 1. South China Sea disputed areas and maritime claims. (AMTI, 2025a).

One of the most contentious issues has been China’s sweeping ‘nine-dash line’ claim over around 90% of the South China Sea. China’s legal position on the nine-dash line is rooted in historical claims dating back to ancient Chinese maritime activities and formal claims published in 1948. China maintains that it has indisputable sovereignty over the South China Sea Islands (the Dongsha Islands, the Xisha Islands, the Zhongsha Islands, and the Nansha Islands) and the adjacent waters based on historical discovery, naming, administration, and territorial control of these islands. According to China’s official position, the nine-dash line came into being for the purpose of confirming and consolidating China’s legitimate rights and interests in the South China Sea, representing historical rights that predate UNCLOS and should be protected under international law. China argues that these historical rights encompass sovereignty over islands, sovereign rights over maritime areas, and other legitimate maritime interests that have evolved over centuries (China’s Position Paper, 2014; Wang, 2024). This claim of historical right, however, has been contested by other claimant states and was deemed invalid in 2016 by the UNCLOS regulations, as per an arbitration case filed by the Philippines (PCA Case No. 2013-19, 2016). China rejected the arbitration tribunal’s jurisdiction and ruling, maintaining that the tribunal exercised its jurisdiction ultra vires, made a ruling with substantial flaws in law and fact, and was politically motivated. China’s position is that territorial sovereignty over maritime features must be determined before maritime rights can be delimited, and that the arbitration ruling cannot affect China’s territorial sovereignty and maritime rights and interests under any circumstances (China’s Position Paper, 2014). This, in turn, has created an enforcement problem because China does not accept the ruling and continues to operate within the disputed areas.

4.1.1 China’s fisheries management and environmental protection measures

In terms of practical law enforcement, China has implemented several measures that it argues are aimed at conserving resources and protecting the environment. Since 1999, China has enforced a summer fishing moratorium in the northern part of the South China Sea, which runs from early May to mid-to-late August or mid-September each year. This moratorium, which China describes as one of its most important policies for fishery conservation and management, is implemented within China’s jurisdictional waters and aims to protect marine ecosystems and prevent overexploitation of fishery resources. Chinese authorities emphasise that this policy reflects China’s commitment to ecological restoration and sustainable development, implementing the governance principle of “taking with restraint, using with moderation, and ensuring lasting abundance” (Wang, 2025). China maintains that the fishing moratorium measures are implemented solely within its actual jurisdictional waters and do not extend to all disputed areas, though neighbouring states have sometimes viewed these enforcement actions differently.

China has also emphasised its role in promoting cooperative marine environmental management in the South China Sea. Chinese officials have called for regional cooperation on fisheries management and environmental protection, as mandated by Article 123 of UNCLOS, which requires states bordering semi-enclosed seas to cooperate in protecting the marine environment and managing fish stocks. China has participated in discussions about establishing Marine Protected Areas and cooperative management mechanisms in the disputed waters, though progress has been limited by the underlying territorial disputes (CSIS, 2017; Kriegl, 2021).

One of the most critical questions of the South China Sea concerns the construction and militarisation of artificial islands by China. Such activities have been viewed as contravening freedom of navigation and are likely to exacerbate regional tensions (Center for Preventive Action, 2024; Lee, 2023). Additionally, the United States, although not a claimant, has conducted a series of freedom of navigation operations to challenge what it views as the enforcement of excessive maritime claims, further complicating the enforcement landscape (US Navy, 2024). Law enforcement in the South China Sea is extremely challenging, with overlapping claims and unmarked boundaries. Littoral states have implemented several enforcement measures, including fisheries protection, environmental monitoring, and counter-piracy operations. However, these activities tend to breed confrontations between the maritime law enforcement agencies of claimant states (Zhang and Bateman, 2017).

4.1.2 Recent developments (2023-2025)

The South China Sea has witnessed continued tensions between 2023 and 2025, with incidents involving multiple claimant states reflecting the ongoing challenges of law enforcement in disputed waters. The period has been marked by confrontations between maritime law enforcement agencies, as well as diplomatic efforts to manage these tensions through bilateral and multilateral mechanisms.

In 2024, several maritime incidents occurred near contested features in the South China Sea, particularly around Second Thomas Shoal and Scarborough Shoal. These incidents involved confrontations between Chinese and Philippine maritime law enforcement vessels during resupply missions. On June 17, 2024, a collision occurred between vessels near Second Thomas Shoal during a Philippine resupply operation to the grounded vessel BRP Sierra Madre. Both China and the Philippines provided differing accounts of the incident, with each side attributing responsibility to the other. China maintained that the Philippine vessels were carrying construction materials intended to reinforce the outpost, while the Philippines characterised the mission as routine resupply for personnel stationed there (Aaron-Matthew, 2025; CFR, 2024).

Following this incident, both countries engaged in diplomatic consultations. According to reports, China and the Philippines reached an informal arrangement regarding resupply missions to Second Thomas Shoal, with no major incidents reported over such missions since mid-2024, suggesting some success in managing tensions through diplomatic channels (Aaron-Matthew, 2025). However, in August 2024, another confrontation occurred near Sabina Shoal involving Chinese and Philippine coast guard vessels. The incident reflected the broader pattern of competing enforcement activities in areas where maritime claims overlap. Both sides maintained their legal positions regarding jurisdiction over the area (Carl, 2025).

Despite these tensions, China and the Philippines have maintained bilateral dialogue mechanisms. In January 2023, during Philippine President Ferdinand Marcos Jr.’s state visit to China, both countries reaffirmed that “maritime issues do not comprise the sum-total of relations between the two countries” and agreed to manage differences through peaceful means. The two sides established a direct communication mechanism between their respective foreign ministries and agreed to strengthen cooperation through the Joint Coast Guard Committee and the Bilateral Consultation Mechanism on the South China Sea. They also committed to further maritime cooperation in environmental protection, marine economy, mitigation of marine debris, and management of microplastics (MOFA-China, 2023).

Both countries have also pursued cooperation in fisheries and marine environmental protection. The Philippines and China signed an Action Plan for Agricultural and Fisheries Cooperation (2023-2025) and agreed to collaborate on sustainable fishing practices and the protection of marine ecosystems. China has proposed joint development schemes in disputed areas, building on earlier cooperative frameworks, such as the 2004 Joint Marine Seismic Understanding (JMSU). However, implementation has faced challenges due to political sensitivities and differing legal positions (MOFA-China, 2023).

The Association of Southeast Asian Nations (ASEAN) has continued efforts to manage the dispute through multilateral diplomacy. In July 2023, ASEAN members and China adopted the Guidelines for Accelerating the Early Conclusion of an Effective and Substantive Code of Conduct in the South China Sea (Hu, 2023). In April 2025, the Philippines hosted another round of Code of Conduct (COC) negotiations in Manila. However, progress remains gradual due to fundamental differences over the COC’s legal nature, scope, and enforcement mechanisms. China has emphasised that the COC should be a non-binding framework developed by regional parties without external interference, while some ASEAN members seek a more binding agreement with clearer enforcement provisions (Philippines DFA, 2025; Carl, 2025).

Alongside these challenges, China and ASEAN have also pursued positive cooperation initiatives. In October 2025, China and ASEAN defence ministers agreed to hold their second joint maritime drill in 2027, following their first exercise in 2018. This agreement reflects both sides’ commitment to maintaining regional stability through practical cooperation. Economic cooperation has also strengthened, with trade between China and ASEAN reaching 5.57 trillion yuan (approximately $785 billion USD) in the first three quarters of 2025, a 9.6% year-on-year increase, with ASEAN remaining China’s largest trading partner (MOFA-China, 2025).

The Philippines has also expanded its security partnerships with external actors, including the United States, Japan, and Australia, conducting joint maritime exercises and strengthening defence cooperation agreements. These partnerships reflect Manila’s strategy of diversifying its security relationships while maintaining diplomatic engagement with China. In May 2025, the Philippines and Japan conducted their second round of joint naval drills. Additionally, the Philippines participated in multilateral exercises with the United States, Australia, and New Zealand in October 2025 (Mishra, 2025).

These developments illustrate the complex and multi-dimensional nature of the South China Sea dispute, where maritime incidents coexist with diplomatic dialogue, bilateral cooperation mechanisms operate alongside multilateral frameworks, and security competition proceeds in parallel with economic integration. The period from 2023 to 2025 demonstrates that, despite ongoing tensions in enforcement activities, all parties continue to engage in dialogue and cooperative initiatives, reflecting a shared interest in managing disputes and preventing escalation.

4.2 East China Sea dispute

The primary actors in the East China Sea are China and Japan, with Taiwan also asserting claims. The issues currently at stake are the issues of sovereignty over the Senkaku/Diaoyu Islands and delimitation of maritime boundaries, including EEZs, as well as continental shelves, respectively (Hall, 2019; Strating, 2021). Currently, Japan administers the Senkaku/Diaoyu Islands; however, both China and Taiwan also claim sovereignty over these islands. This argument emerged in 2012 when the Japanese government acquired three of the islands from private owners, resulting in a surge in tensions and maritime confrontations (as shown in Figure 2) (Jie, 2023).

Figure 2

Figure 2. East China Sea disputed areas and maritime claims. (AMTI, 2025b).

4.2.1 Differing legal positions and maritime boundary approaches

The legal basis of the claims by the parties differs fundamentally. Japan maintains that it incorporated the islands in 1895 as terra nullius (land belonging to no one), following surveys that confirmed they were uninhabited and showed no trace of Chinese control. Japan argues that the islands have been under continuous and peaceful Japanese administration since then, except for the period of US administration from 1945 to 1972, and that they are an inherent part of Japanese territory. China, conversely, argues it has historical possession of the islands dating back centuries, asserting that the islands were discovered, named, and utilised by China during the Ming Dynasty (1368-1644) and that they were included in China’s coastal defence system. China maintains that Japan illegally seized the islands during the Sino-Japanese War (1894-1895) and that they should have been returned to China following World War II under the Potsdam Declaration and Cairo Declaration. These differing historical and legal narratives create fundamental disagreements over sovereignty that complicate law enforcement activities in the surrounding waters (Ikeshima, 2014; Hall, 2019).

The conflicting approaches to maritime boundary delimitation further complicate law enforcement in the East China Sea. Japan advocates for the median line (equidistance) principle as the basis for delimiting the EEZ between the two countries, which would place the boundary approximately midway between the coastlines of Japan and China. China, however, rejects this approach and applies the principle of natural prolongation of its continental shelf, arguing that China’s continental shelf extends naturally to the Okinawa Trough, which reaches depths of over 2,700 meters. According to China’s position, the natural extension of its land territory extends toward and beyond the median line claimed by Japan. This fundamental disagreement over delimitation principles has resulted in overlapping claims to maritime areas with significant hydrocarbon potential, particularly around gas fields such as Chunxiao/Shirakaba (Gau, 2019; Ross, 2016).

4.2.2 Cooperative Initiatives

Despite sovereignty disputes, both countries have also pursued practical cooperation. In 2008, China and Japan reached an understanding on joint development, establishing a cooperation zone of approximately 2,600 square kilometres and arrangements for Japanese participation in the Chunxiao/Shirakaba field. However, implementation has faced challenges due to differing interpretations and domestic political considerations in both countries (Dang, 2025; CFR, 2020). The 1997 China-Japan Fisheries Agreement established joint fishing zones and a bilateral fisheries committee, representing an important functional arrangement allowing fishing activities while boundary disputes remain unresolved. Therefore, it is fair enough to comment that enforcement continues to face challenges due to overlapping jurisdictional claims.

4.2.3 Recent developments (2023-2025)

Both countries have strengthened crisis management mechanisms. In May 2023, China and Japan operationalised a direct defence ministry hotline as part of their Maritime and Aerial Communication Mechanism, designed to prevent incidents from escalating through information exchange and dialogue. This mechanism includes annual defence meetings, secure communication channels, and protocols for vessel-to-vessel communication (MOD-Japan, 2023; Kawakami, 2023). Economic cooperation has also advanced. In May 2025, China agreed to resume imports of Japanese seafood following technical consultations, with actual exports recommencing in June 2025. Both countries also implemented a bilateral agreement on animal health cooperation in July 2025 (MOFA-Japan, 2025; Reuters, 2025).

These developments demonstrate that, while fundamental disagreements over sovereignty and boundaries persist, both countries continue to develop practical mechanisms to manage tensions and pursue mutually beneficial cooperation in areas such as fisheries, resource development, and crisis communication. The East China Sea case illustrates how states can develop functional arrangements for cooperation and tension management, even when core disputes remain unresolved, provided that continued dialogue and mutual restraint are maintained to ensure stability.

4.3 Comparative insights: South China Sea vs. East China Sea

While both disputes involve overlapping maritime claims governed by UNCLOS, a systematic comparison reveals important differences that illuminate how contextual factors shape enforcement dynamics and cooperation prospects.

4.3.1 Dispute structure and legal complexity

The most fundamental difference concerns the structure of disputes. The South China Sea involves multiple overlapping claimants (China, Vietnam, Philippines, Malaysia, Brunei, Taiwan) with diverse and often incompatible legal positions. China’s nine-dash line overlaps with EEZ and continental shelf claims of multiple Southeast Asian states. This multilateral, multi-layered structure creates extraordinary legal complexity, as any bilateral resolution potentially affects third parties. The East China Sea dispute is primarily bilateral (China-Japan), with a clearer legal structure. The core issues—Senkaku/Diaoyu Islands sovereignty and EEZ/continental shelf delimitation—involve two principal parties with well-articulated positions (median line vs. natural prolongation). This simpler structure enables more focused negotiations and more precise bilateral mechanisms.

Implication—The multilateral character of the SCS necessitates multilateral or “minilateral” solutions (e.g., ASEAN-China frameworks), whereas the bilateral ECS is more amenable to traditional bilateral diplomacy. This explains why bilateral mechanisms, such as the 2008 Joint Development Understanding and the 2023 Defence Hotline, have emerged in the ECS, whereas SCS efforts focus on broader frameworks, such as the Code of Conduct.

4.3.2 Resource distribution and cooperation feasibility

Resource distribution patterns differ significantly. The South China Sea contains widely distributed fishery resources across vast areas, plus potential hydrocarbon deposits in multiple locations. This dispersed distribution means enforcement activities span enormous maritime space, increasing encounter frequency and complicating joint management. The East China Sea features more concentrated strategic resources, particularly gas fields near the median line/continental shelf boundary. Concentrated resources are more amenable to joint development frameworks, as demonstrated by the 2008 understanding. The smaller geographic scope makes enforcement activities more predictable and containable.

Implication—Concentrated ECS resources enabled the 2008 joint development agreement, whereas dispersed SCS resources require broader regional frameworks. The SCS would benefit from a zoned approach—identifying specific areas (e.g., Reed Bank) for targeted joint development agreements rather than attempting comprehensive solutions across the entire sea.

4.3.3 Enforcement mechanisms and incident management

Enforcement patterns reveal contrasting dynamics. In the SCS, enforcement involves multiple actors’ coast guards, maritime militias, and naval forces operating across vast areas. Incidents are frequent and diverse, involving various combinations of claimants. The 2016 arbitration ruling added legal complexity, with the Philippines invoking it while China rejects it, creating parallel legal frameworks (De Castro, 2022). In the ECS, enforcement is more structured and ritualised. Chinese and Japanese coast guard vessels conduct regular patrols around the Senkaku/Diaoyu Islands in accordance with established patterns. The 2023 Maritime and Aerial Communication Mechanism provides formal channels for de-escalation. Incidents, while occurring, tend to follow predictable patterns and are managed through established protocols.

Implication—The ECS’s more structured enforcement environment and functional communication mechanisms offer lessons for the SCS. Establishing operational protocols—such as Coast Guard communication hotlines, incident notification procedures, and professional codes of conduct—could reduce the risk of SCS escalation. The ASEAN Coast Guard Forum represents a positive step in this direction.

4.3.4 Cooperative framework effectiveness

Both regions have developed cooperative mechanisms, but with different levels of effectiveness. In the East China Sea, several cooperative initiatives have achieved functional operational status despite ongoing sovereignty disputes. The 1997 China-Japan Fisheries Agreement established a functional framework for managing fishing activities in overlapping areas, and although implementation faces periodic challenges, it continues to provide a working arrangement for resource management. The 2008 Joint Development Understanding demonstrated political will for resource cooperation by establishing a cooperation zone of approximately 2,600 square kilometres and arrangements for Japanese participation in the Chunxiao/Shirakaba field development.

The 2023 Maritime and Aerial Communication Mechanism represents a significant achievement, providing an operational mechanism that reduces the risk of military miscalculation through direct defence ministry communication channels. Additionally, the 2025 resumption of Japanese seafood imports to China demonstrates that economic cooperation can progress despite political tensions. In contrast, the South China Sea faces more significant cooperative challenges. The 2002 Declaration on Conduct remains non-binding, lacks effective enforcement mechanisms, and has been frequently violated by various parties. The ASEAN-China Code of Conduct negotiations, ongoing since 2013, have experienced slow progress due to fundamental disagreements over the agreement’s binding nature, scope, and enforcement provisions. While bilateral mechanisms such as the China-Philippines Bilateral Consultation Mechanism show promise, their implementation has been inconsistent.

The key difference between the two regions is clear: the East China Sea has achieved functional cooperation in specific areas despite unresolved sovereignty issues, whereas cooperation in the South China Sea remains largely aspirational, with limited operational content. This comparison carries important implications. The East China Sea demonstrates that China’s policy of “setting aside disputes and pursuing joint development” can yield practical results when cooperation is confined to specific technical areas rather than pursued through comprehensive political settlements. The South China Sea would benefit from adopting a similar approach by disaggregating issues—pursuing cooperation on fisheries management, environmental protection, and search-and-rescue operations separately from sovereignty disputes, rather than linking all issues together in comprehensive frameworks that prove challenging to achieve.

4.3.5 Cross-application of lessons

Several important lessons from the East China Sea are directly applicable to the South China Sea context. First, the establishment and operationalisation of the 2023 defence hotline between China and Japan demonstrates that crisis communication mechanisms can effectively reduce escalation risks even amid unresolved disputes. For the South China Sea, this suggests the value of establishing a multilateral coast guard hotline connecting the maritime law enforcement agencies of all claimant states, providing formal channels for incident notification, clarification, and de-escalation.

Second, the success of the 1997 fisheries agreement and 2008 joint development understanding shows that functional cooperation in specific sectors is possible when sovereignty is “set aside” for practical purposes. The South China Sea could benefit from developing similar sector-specific frameworks for fisheries management, environmental monitoring, and search-and-rescue operations that operate independently of sovereignty settlements, allowing practical cooperation to proceed while fundamental political disagreements remain unresolved.

Third, the substantial China-Japan bilateral trade relationship provides economic incentives for conflict management, as demonstrated by the 2025 seafood trade resumption. For the South China Sea, this suggests the value of strengthening ASEAN-China economic integration and emphasising the economic costs of conflict to reinforce political incentives for restraint.

Conversely, the South China Sea experiences offer valuable lessons for the East China Sea. The role of ASEAN as a multilateral forum, despite its limitations and internal divisions, has provided diplomatic platforms that help reduce bilateral tensions by fostering dialogue, building confidence, and promoting collective engagement with China. For the East China Sea, this suggests that greater involvement of regional frameworks such as ASEAN + 3 or the East Asia Summit could usefully supplement bilateral China-Japan mechanisms by providing additional forums for dialogue and reducing the bilateral intensity of the dispute.

Additionally, the experience with the 2016 South China Sea arbitration demonstrates the limited utility of third-party adjudication when parties fundamentally disagree on legal positions and one party refuses to participate. While the arbitral tribunal’s ruling is legally significant, it has not resolved the dispute in practice. For the East China Sea, this confirms that negotiated solutions, even if partial or provisional, are likely to be more sustainable and effective than imposed legal outcomes, reinforcing the value of continued bilateral dialogue and functional cooperation.

4.3.6 Synthesis

This comparative analysis demonstrates that enforcement dynamics are shaped by structural factors, including the number of claimants, resource distribution, communication mechanisms, clarity of the legal framework, and external power involvement. The relatively more successful ECS cooperative mechanisms correlate with simpler dispute structure, concentrated resources, a bilateral framework, and established communication channels. The more challenging SCS environment reflects multilateral complexity, dispersed resources, a contested legal framework, and internationalised strategic competition. Effective SCS dispute management requires adapted approaches: multilateral frameworks, zoned resource cooperation, operational protocols to manage complexity, and mechanisms accommodating external actors’ legitimate interests. Both cases confirm that international law provides necessary but insufficient guidance—legal frameworks must be operationalised through political mechanisms tailored to each dispute’s specific characteristics.

5 Policy recommendations

The law enforcement challenges in disputed maritime areas are varied and complicated. Drawing on successful international precedents and evidence-based best practices, this study suggests the following policy recommendations to enhance international cooperation and promote sustainable law enforcement in the disputed maritime areas.

5.1 Enhancing international cooperation

Practical international cooperation can manage disputes and facilitate the peaceful resolution of maritime conflicts. Regional organisations and multilateral forums provide necessary platforms for dialogue and confidence-building measures. While regional attempts have been made through the ASEAN and the East Asia Summit, sustained progress requires institutionalised mechanisms with clear mandates.

5.1.1 Empirical evidence from successful regional mechanisms

Several regional maritime security cooperation frameworks demonstrate the viability of this approach:

First, the Djibouti Code of Conduct (DCoC) and Jeddah Amendment provide a successful model of legally binding regional cooperation. Adopted in 2009 by 21 signatory states from Africa and the Middle East, the DCoC established a framework for information sharing, joint operations, and capacity-building to combat piracy and armed robbery in the Western Indian Ocean and the Gulf of Aden. The 2017 Jeddah Amendment expanded its scope to address broader maritime crimes, including illegal, unreported, and unregulated (IUU) fishing, human trafficking, and environmental crimes. The framework has established Regional Coordination Operation Centres (RCOCs) in Seychelles and other locations, enabling coordinated responses to maritime threats. Since its implementation, piracy incidents in the region have declined significantly, demonstrating the effectiveness of structured regional cooperation.

Second, the ASEAN Coast Guard Forum (ACF), established in 2022, represents an emerging regional dialogue mechanism specifically designed to foster cooperation among coast guard agencies in Southeast Asia. Through three annual meetings (2022-2024), the ACF has developed draft Terms of Reference for Working Groups on Capacity Building, Information Sharing, and Operational Cooperation, as well as a proposed Southeast Asia Protocol of Engagement at Sea for Coast Guard and Maritime Law Enforcement (SEA-PEACE). The forum facilitates joint table-top exercises, state-to-state cooperation agreements, and training programs covering search and rescue, safety protocols, and equipment operation.

Third, the China-Japan Maritime and Aerial Communication Mechanism, operationalised in May 2023, demonstrates how bilateral hotlines can reduce tensions even in disputed waters. This mechanism includes annual defence meetings, direct hotline communications, and vessel-to-vessel communication protocols, enabling information exchange and preventing incidents from escalating.

Considering the above, it is recommended that a dedicated East and South China Sea Maritime Security Forum be established, bringing together all claimant states, regional organisations (such as ASEAN), and relevant international bodies. This forum should develop information-sharing protocols, joint training programs for law enforcement agencies, and collaborative arrangements for search and rescue operations, following the successful DCoC model.

5.2 Strengthening legal frameworks

While UNCLOS provides a comprehensive regime for maritime governance, ambiguities remain regarding law enforcement in contested areas (Nguyen, 2022). More precise legal instruments specifying the rights and obligations of coastal states in disputed areas can reduce uncertainties and prevent escalation.

5.2.1 Empirical evidence from binding regional agreements

Several precedents demonstrate the feasibility of binding regional maritime agreements:

First, joint Fisheries Agreements have successfully managed resource access in disputed waters. The 1997 China-Japan Fisheries Agreement established a joint fishing zone (Provisional Measures Zone) and a bilateral fisheries committee, allowing fishermen from both nations to operate in designated overlapping areas while broader boundary disputes remain unresolved. Similarly, the 1998 China-South Korea fisheries agreement established cooperative management mechanisms in the Yellow Sea (Xue, 2005). Although implementation faces challenges, these agreements provide functional arrangements that prevent escalation.

Second, the 2008 Understanding on Japan-China Joint Development in the East China Sea established a joint development zone of approximately 2,600 square kilometres for hydrocarbon resources, demonstrating that states can cooperate on resource extraction despite sovereignty disputes.

Third, regional Environmental Protection Conventions provide additional models (Khan and Chang, 2021). The Barcelona Convention (Mediterranean Sea), the OSPAR Convention (North-East Atlantic), and the Nairobi Convention (Eastern African Region) have established legally binding frameworks for marine environmental protection, along with institutional mechanisms for implementation and compliance monitoring (Durden et al., 2018).

Considering the above, it is recommended that a regional Code of Conduct for the East and South China Seas be developed, modelled on the DCoC framework, to establish binding obligations for peaceful conflict resolution, transparency in enforcement activities, and prior notification of major activities in disputed areas. This Code should be accompanied by institutional mechanisms, including a joint maritime information centre and regular high-level consultations, building on the existing ASEAN-China COC negotiations while incorporating lessons from successful regional frameworks.

5.3 Promoting sustainable practices

Sustainable management of marine resources and protection of the marine environment in disputed areas are essential for reducing tensions and facilitating cooperative solutions (Daoudy, 2023). Unilateral exploitation or environmental degradation can escalate disputes and undermine prospects for peaceful resolution.

5.3.1 Empirical evidence from cooperative resource management

Multiple case studies demonstrate successful cooperation on marine resource management despite unresolved sovereignty issues:

First, the Eastern Tropical Pacific Marine Corridor (CMAR), established in 2004 by Ecuador, Costa Rica, Colombia, and Panama through the San José Declaration, created a voluntary regional cooperation mechanism for conserving marine biodiversity. This framework enables coordinated management of shared marine ecosystems without requiring resolution of all boundary disputes, focusing instead on practical cooperation for environmental protection.

Second, joint Fishery Management Zones have been successfully implemented in several regions. The Scotland-Faroe Islands agreement and various bilateral arrangements in the North Sea provide decentralised fishery management models where states coordinate regulations while maintaining separate jurisdictions. These precedents offer adaptable frameworks for the East and South China Seas.

Third, transboundary Marine Protected Areas (MPAs) have been established in several regions despite political tensions. The Mediterranean Sea’s Special Protected Areas, established under the Barcelona Convention, operate on the principle that “the establishment of intergovernmental cooperation does not prejudice any outstanding legal or political issues regarding the determination of state jurisdiction,” allowing environmental cooperation to proceed independently of sovereignty disputes. This “without prejudice” approach, established by the Antarctic Treaty precedent, enables states to cooperate on conservation while maintaining their legal positions.

Lastly, the 2020 Eastern Mediterranean EEZ Agreements between Cyprus-Egypt, Cyprus-Lebanon, and Cyprus-Israel include provisions for managing hydrocarbon resources that straddle boundaries. These agreements require parties to notify each other when resources are identified within 10 kilometres of the EEZ boundary and to share technical information, as successfully demonstrated when Egypt discovered the Zohr gas field in 2015.

Considering the above successful cooperation, it is recommended to develop joint management frameworks for key marine ecosystems in disputed areas, including:

◼ Pilot MPAs using the “without prejudice” principle from Mediterranean precedents, focusing initially on areas of high ecological value where all parties recognise conservation benefits.

◼ Joint fishery management committees, following the China-Japan and China-South Korea models, establish catch limits, closed seasons, and enforcement protocols coordinated through bilateral or multilateral mechanisms.

◼ Environmental Impact Assessment (EIA) notification protocols, similar to those in the Eastern Mediterranean energy agreements, require parties to share information about planned activities that may impact shared ecosystems.

◼ Collaborative scientific research programs on fisheries stocks, marine ecosystems, and climate change impacts, building trust through joint data collection and analysis.

These initiatives should prioritise practical cooperation over final delimitation, recognising that effective resource management can proceed while sovereignty issues remain under negotiation.

6 Conclusion

This study has examined law enforcement challenges in disputed maritime areas through a comparative analysis of the South China Sea and the East China Sea, generating analytical insights into how international law operates in contested maritime spaces, how contextual factors shape enforcement outcomes, and which policy approaches show promise based on empirical evidence.

6.1 Synthesis of key analytical findings

The comparative analysis reveals four principal findings. First, UNCLOS Articles 74(3) and 83(3) create a legally ambiguous space that permits competing interpretations, undermining their effectiveness in guiding state conduct. While these provisions require states to “make every effort to enter into provisional arrangements” and “refrain from actions that jeopardise or hamper final agreement,” both case studies demonstrate that states disagree fundamentally on what constitutes compliance. States contest what “every effort” entails, what forms “provisional arrangements” should take, and what actions “jeopardise” final settlements. This interpretive flexibility enables states to claim compliance while pursuing divergent strategies, revealing that international law in disputed maritime spaces functions less as a determinative constraint and more as a contested normative framework within which states advance interests through strategic legal argumentation.

Second, contextual factors critically shape enforcement outcomes. The East China Sea’s bilateral structure has enabled focused negotiations producing functional results: the 1997 fisheries agreement, 2008 joint development understanding, and 2023 defence hotline. The South China Sea’s multilateral structure complicates cooperation, as bilateral arrangements may disadvantage third parties, creating collective action problems. The East China Sea’s concentrated hydrocarbon resources proved amenable to joint development frameworks targeting specific gas fields, whereas the South China Sea’s dispersed resources across vast areas resist comprehensive management. The East China Sea’s established communication mechanisms provide forums for managing tensions, while the South China Sea’s weaker institutionalisation leaves fewer channels for de-escalation. These variations demonstrate that enforcement dynamics are determined not solely by legal frameworks, which are similar across cases, but by institutional and structural factors that vary across contexts.

Third, functional cooperation can proceed despite unresolved sovereignty when appropriate principles are applied. Both cases show that sovereignty disputes and practical cooperation are not mutually exclusive. The East China Sea demonstrates that fisheries can be jointly managed, resources jointly developed, and military communication established, even as sovereignty over the Senkaku/Diaoyu Islands remains contested. The South China Sea shows emerging cooperation on search-and-rescue, environmental protection, and bilateral fisheries arrangements despite unresolved territorial claims. The enabling principle is the “setting aside disputes and pursuing joint development” or “without prejudice” approach, which allows cooperation on functional issues while explicitly reserving the parties’ legal positions. This inverts the traditional sequence in international law—functional cooperation can precede political settlement and may even facilitate eventual settlements by building trust and creating shared interests.

Fourth, empirical precedents from other regions demonstrate the feasibility of binding regional cooperation frameworks. The Djibouti Code of Conduct, Mediterranean environmental agreements, bilateral fisheries frameworks, and joint development zones show that legally binding cooperation is achievable even in complex geopolitical environments when agreements feature focused mandates, institutional mechanisms for regular engagement, “without prejudice” clauses protecting legal positions, and emphasis on practical benefits rather than final political settlements.

6.2 Scholarly contributions

This research advances academic knowledge in four ways. It provides the first systematic comparative analysis of law enforcement challenges in the South China Sea and East China Sea within a unified analytical framework, revealing patterns that single-case studies cannot illuminate: how dispute structure affects cooperation prospects and how resource distribution influences the feasibility of joint development. It bridges the gap between doctrinal legal analysis and empirical enforcement practice, showing how legal ambiguities create space for competing enforcement strategies and where law succeeds or fails in constraining behaviour. It advances scholarly understanding through a comprehensive analysis of developments from 2023 to 2025, including crisis communication mechanisms, Code of Conduct negotiations, and recent enforcement incidents. It provides evidence-based policy analysis grounded in successful precedents from other regions rather than abstract ideals, enhancing practical utility for policymakers.

6.3 Policy implications linked to evidence

The policy recommendations advanced in this study derive directly from analytical findings and empirical precedents. The proposal to establish an East and South China Sea Maritime Security Forum is grounded in the Djibouti Code of Conduct’s demonstrated success with 21 signatory states achieving measurable piracy reduction, the emerging ASEAN Coast Guard Forum’s regional dialogue function, and the China-Japan defence hotline’s demonstrated value. The recommendation to develop a binding regional Code of Conduct draws on the Mediterranean Special Protected Areas’ binding cooperation despite political disputes, the functional frameworks of bilateral fisheries agreements, and the resource notification protocols of Eastern Mediterranean energy agreements. The proposal to promote joint management frameworks and Marine Protected Areas is based on the Eastern Tropical Pacific Marine Corridor’s regional environmental cooperation, Scotland-Faroe Islands fisheries management models, and the 2008 East China Sea joint development demonstration of resource cooperation feasibility. Each recommendation is thus empirically grounded rather than aspirational, supported by precedents demonstrating feasibility.

6.4 Future directions

The East and South China Sea cases demonstrate that disputed maritime areas present enduring challenges for international law and regional stability, yet they also reveal grounds for measured optimism. Functional cooperation is emerging through fisheries agreements, environmental initiatives, and crisis communication mechanisms. Empirical precedents demonstrate that binding regional frameworks can operate effectively despite political tensions. Success requires recognising that international law in disputed maritime spaces is not self-executing but must be operationalised through context-appropriate institutions, sustained dialogue, and political commitment to managing tensions while pursuing shared interests. Whether these seas become zones of protracted conflict or models of cooperative management will depend on whether parties embrace the lessons this comparative analysis illuminates: that cooperation in specific functional areas can proceed immediately while sovereignty negotiations continue, that crisis communication mechanisms reduce escalation risks even when fundamental disagreements persist, and that economic interdependence reinforces incentives for peaceful dispute management. The analytical framework and empirical insights developed here provide guidance not only for the South China Sea and East China Sea but for disputed maritime areas globally, where states must navigate the gap between legal principle and practical enforcement.

Data availability statement

The original contributions presented in the study are included in the article/supplementary material. Further inquiries can be directed to the corresponding author/s.

Author contributions

MIK: Conceptualization, Writing – original draft, Writing – review & editing, Investigation.

Funding

The author(s) declared that financial support was not received for this work and/or its publication.

Conflict of interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The author(s) declared that Generative AI was not used in the creation of this manuscript.

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Footnotes

1. ^ It refers to the cases with an exception where the Parties disagree to validate or existence an already drawn boundary line, as provided in the case of the Guinea-Bissau/Senegal arbitration. “Award reprinted in RGDIP 204 (1990).”
2. ^ The seas include the “Sea of Okhotsk, 614,000 nm²,” “East Sea of Korea (or the Sea of Japan), 44,500 nm²,” and the “Yellow Sea and the East China Sea, encompassing 362,000 nm².”
3. ^ See “the Chinese Law on the Territorial Waters and their Contiguous Areas (Article 6), South Korea’s Law on the Territorial and Contiguous Area (Article. 5) and its Presidential Decree (Article 4).”
4. ^ “It states that the delimitation of the EEZ between States with opposite or adjacent coasts shall be affected by agreement on the basis of international law—in order to achieve an equitable solution.”
5. ^ See for more details, “Articles 6–7 of the 1997 China–Japan Fisheries Agreement.”
6. ^ Since the beginning of the Third UNCLOS made it clear that the maritime areas’ extension seawards as to the exclusive rights of the coastal States would increase disputes in the maritime areas and that the interim measures would be welcome; “R. Lagoni, Interim Measures Pending Maritime Delimitation Agreements, AJIL 78 (1984), 345 et seq., at 349.”
7. ^ As maintained in the Guyana/Suriname case’s Arbitral Tribunal, the coastal States can carry a condition for the resumption or starting of the negotiations in a case where the other States cease conduct that could possibly jeopardise or hamper the reaching of an agreed solution. “Guyana/Suriname Award (note 1), para. 476.”
8. ^ “Para no. 476 of the Guyana/Suriname Award.”
9. ^ “Para no. 476 of the Guyana/Suriname Award.”
10. ^ “Para no. 477 of the Guyana/Suriname Award.”
11. ^ “Para no. 476 of the Guyana/Suriname Award.”
12. ^ “Para no. 465 of the Guyana v Suriname Award.”
13. ^ It is not a common practice to grant licenses for fishing in contested areas by more than one State; for instance, both Nicaragua and Honduras had granted licenses to fishermen in the disputed islands in the Caribbean.
14. ^ See for more details, Article 61 of UNCLOS, https://www.un.org/Depts/los/convention_agreements/texts/unclos/closcont.htm, accessed August 11, 2025.
15. ^ “Para no. 467 of the Guyana v Suriname award.
16. ^ See for more details, Article 30 of the Draft Articles on State Responsibility, https://legal.un.org/ilc/texts/instruments/english/commentaries/9_6_2001.pdf, accessed July 12, 2025.
17. ^ See for more details, Article 51 of the Draft Articles on State Responsibility, https://legal.un.org/ilc/texts/instruments/english/commentaries/9_6_2001.pdf, accessed July 12, 2025.
18. ^ See for more details, Article 50 of the Draft Articles on State Responsibility, https://legal.un.org/ilc/texts/instruments/english/commentaries/9_6_2001.pdf, accessed July 12, 2025.
19. ^ See for more details, as laid down in Article 49 para no. 3, Draft Articles on State Responsibility, https://legal.un.org/ilc/texts/instruments/english/commentaries/9_6_2001.pdf, accessed July 12, 2025.
20. ^ See for more details, Article 50, para no. 1 of the Draft Articles on State Responsibility, https://legal.un.org/ilc/texts/instruments/english/commentaries/9_6_2001.pdf, accessed July 12, 2025.

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