2023/51 “What Has China’s Lawfare Achieved in the South China Sea?” by Christian Schultheiss

China’s strategy in the South China Sea aims to enforce its invalidated claims, whereas recent legal actions by Southeast Asian claimant states seek to clarify claims and incentivise dispute settlement based on the United Nations Convention on the Law of the Sea (UNCLOS). This photo taken on 23 April 2023 shows the Philippine coast guard vessel BRP Malapascua (R) manoeuvering as a Chinese coast guard ship cuts its path at Second Thomas Shoal in the Spratly Islands in the disputed South China Sea. Photo: Ted ALJIBE AFP.


  • Analyses of the South China Sea (SCS) disputes often use the term “lawfare” to describe the greatly diverging activities of China, the Philippines, Malaysia, Vietnam, and the US, obscuring the normative differences between these states’ policies.
  • China’s lawfare strategy in the SCS aims to enforce its invalidated claims, whereas recent legal actions by Southeast Asian claimant states seek to clarify claims and incentivise dispute settlement based on the United Nations Convention on the Law of the Sea (UNCLOS).
  • Rather than promoting a comprehensive re-writing of the law of the sea, China tries to advance historically based particularistic claims. After many decades of disputes in the SCS, no alternative Chinese vision for the law of the sea beyond its particularistic claims has emerged.
  • Traditional legal processes, especially the 2016 South China Sea arbitration ruling, helped provide clarification of the applicable law, thereby debunking any legal cover for the enforcement of China’s claims in the SCS.
  • Explicit international support for China’s maritime claims in the SCS beyond the applicable zones as specified by UNCLOS is waning while explicit support for various substantive findings of the arbitration ruling is increasing.
  • China has effectively changed the status quo through reclamation and building of outposts on some features in the SCS, but it has not succeeded in creating the presumption that Chinese enforcement of its invalidated claims is anywhere near legality.

*Guest writer, Christian Schultheiss, is Senior Research Fellow at the Max Planck Institute for Comparative Public Law and International Law, research group European Security Revisited (ENSURE).

ISEAS Perspective 2023/51, 10 July 2023

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‘Lawfare’ is a popular term to generally describe different legal strategies of states to defend and promote their maritime rights and interests in the South China Sea (SCS). Dunlap originally defined ‘lawfare’ as “the strategy of using – or misusing – law as a substitute for traditional military means to achieve an operational objective.”[1] This definition notwithstanding, the literature has not produced a consensus on what types of activities qualify as lawfare and whether lawfare refers to a normatively negative, neutral or recommended practice.[2] In analyses of the SCS disputes, many types of activities have been labelled as ‘lawfare’, including China’s activities[3] and legal arguments to assert its maritime claims, the Philippines’ initiation of arbitral proceedings against China, Malaysia and Vietnam’s joint submission for an extended continental shelf, and US freedom of navigation operations (FONOPs). Such a liberal use of the term obscures the normative difference in the policies and practices of these countries, so much so that some legal experts have lamented that scholarship has “lost control of the concept of lawfare”,[4] and this applies to the SCS. This Perspective examines how China’s lawfare in the SCS is different from the legal actions undertaken by other countries, especially Southeast Asian claimant states. It also assesses the extent to which China’s lawfare has contributed to the realisation of its objectives in the SCS.


China’s excessive, yet ambiguous, claims in the SCS are illustrative of China’s instrumental use of legal language. China has adjusted the legal justification for its maritime claims even after the award of the South China Sea arbitration of 12 July 2016 invalidated the claims to maritime zones beyond the normal zones under UNCLOS. In a statement of 12 July 2016, China insisted on territorial claims to features, including the Paracel, Spratly and Pratas Islands and the Macclesfield Bank, and claims to a territorial sea, exclusive economic zone (EEZ), continental shelf (CS) and historic rights inside the Nine-dash line.[5]. In Notes Verbales to the Secretary-General of the UN of 2020 and 2021, China has then added a reference to “general international law” and “outlying archipelagos”.[6] Its Note Verbale dated 16 August 2021 says that “the regime of continental States’ outlying archipelagos is not regulated by UNCLOS, and the rules of general international law should continue to be applied in this field.” China now defends the alleged existence of “rights established in the long course of history” with reference to “general international law”. China’s argument relies on a provision in the Preamble of UNCLOS which states that “matters not regulated by this Convention continue to be governed by the rules and principles of general international law”.[7] In its Notes Verbales dated 29 July 2020, 18 September 2020, 28 January 2021 and 16 August 2021, China insists that “general international law” is the legal basis for drawing “territorial sea baselines” around China’s claimed features, including submerged reefs, in the SCS.[8] China’s reference to this provision ostensibly invokes an alternative legal basis for its claims.

Yet, the matters regarding the extent of maritime rights and baselines are comprehensively regulated by UNCLOS. Based on UNCLOS, the 2016 arbitral tribunal has clarified the types and the maximum extent of maritime zones that China can claim.[9] The tribunal discussed in detail the differences between an “island” that generates entitlement to an EEZ and CS, and a “rock” that generates entitlement to only a territorial sea.[10] UNCLOS also regulates the question of baselines, i.e., the “normal baseline” is the “low-water line along the coast” (Art. 5); “straight baselines” can be used where the “coastline is deeply intended and cut into, or if there is a fringe of islands along the coast in its immediate vicinity” (Art. 7 (1)); and only archipelagic states “may draw straight archipelagic baselines” subject to further provisions (Art. 47). China’s insistence on “territorial sea baselines” around “islands and reefs” based on a “long established practice” and “general international law”[11] is a slightly reframed version of positions that the South China Sea arbitral tribunal has already rejected. The arbitral tribunal did not accept the view that China can enclose the Spratlys within archipelagic or straight baselines – neither under UNCLOS nor under customary international law.[12] Several states, including the Philippines, Indonesia, Malaysia, Vietnam, the US, Australia, France, Germany, the United Kingdom, Japan, and New Zealand, have therefore expressed their opposition to China’s insistence on invalidated claims, and stated their support for various aspects of the tribunal’s ruling.[13]

In China’s view, its Southeast Asian neighbours must make room for China’s historically based claims to maritime zones even after the arbitration ruling decided that these claims are inconsistent with UNCLOS and customary law of the sea. Some scholars see this assertion as an attempt to promote an alternative vision for the law of the sea.[14] However, this vision has arguably remained a quest for enforcing particularistic claims rather than promoting a comprehensive re-writing of the law of the sea. After decades of disputes in the SCS, no alternative Chinese vision for the law of the sea beyond its particularistic claims has emerged. In China’s reference to “rights formed in the long course of history”, there is no indication that China believes that other states can claim historic rights too. China’s use of legal language in defence of these claims does not engage in a quest for a universally accepted interpretation of the rule of law at sea. The scope of these particularistic claims, though, is such that they would upend fundamental balances underlying UNCLOS, especially the fact that no state is allowed to claim maritime rights beyond the normal limits or the balance between exclusive rights of coastal states and navigational rights of user states. Even though Chinese sources and documents repeatedly affirm China’s compliance with UNCLOS,[15] China’s claims are so excessive that they would multiply the normal entitlements provided for under UNCLOS.

What makes China’s lawfare activities distinctive from those of other states in the legal domain of the SCS?

First, the instrumental use of law is not peculiar to China’s activities. US FONOPs in the SCS have been called ‘lawfare’ based on the argument that these operations merely “instrumentalise law for furthering parochial political interests, including military objectives”.[16] According to this argument, FONOPs “ostensibly [serve] to further the rule of law over the rule of force” while in reality serving political and strategic interests. Granted, the idea of instrumentalising law is regularly evoked as a characteristic element of lawfare.[17] However, this view, which considers a certain practice as lawfare merely because it uses law as an instrument, sets the threshold for lawfare too low. An instrumental use of law – such as US FONOPs, which are allowed under UNCLOS (Art. 87 and Art. 90) – is neither inconsistent per se with an interest of acting within a legal order nor is it necessarily reproachable.

The Philippines’ decision to launch arbitral proceedings against China – supposedly an instance of the Philippine lawfare strategy – is another case in point. This type of lawfare reflects “the recognition…of the (actual or potential) utility of international law in shaping, constraining, and altering the behaviour of states”.[18] According to this argument, the Philippines’ initiation of arbitration deserves the label ‘lawfare’ because it served the Philippines strategically as the option of last resort. Yet, the Philippines’ recourse to arbitration under Annex VII of UNCLOS is entirely permissible and a right provided for under UNCLOS. According to the UN General Assembly’s Manila Declaration, “[r]ecourse to judicial settlement of legal disputes, particularly referral to the International Court of Justice, should not be considered an unfriendly act between States.”[19] It is therefore questionable whether the term ‘lawfare’ should be used for legitimate legal actions such as arbitral proceedings. The joint submission of Malaysia and Vietnam for an extended continental shelf to the Commission for the Limits of the Continental Shelf (CLCS) has also been characterised as lawfare.[20] The joint submission, however, is a normatively recommended practice which is within the exercise of the rights and obligations of coastal states under Art. 76(8) of UNCLOS. It is part of the legal processes that can indeed incentivise the settlement of disputes, since these legal processes are used to communicate claims, to clarify their legal basis, and to establish law as a framework for negotiations and interactions.[21]

China’s activities in the legal domain starkly contrast with those of the Philippines or Malaysia and Vietnam both factually and normatively. The former is a type of lawfare that obscures claims and insists on invalidated claims whereas the latter tries to clarify claims and incentivise dispute settlement based on UNCLOS provisions.


A key objective of China’s lawfare in the SCS is to provide a rhetorical cover for its changes of the factual status quo.[22] However, the fact that China has effectively changed the status quo, for instance by building outposts on islands or increasing the frequency and reach of coast guard patrols, does not mean that China has succeeded in creating the presumption that the enforcement of its invalidated claims is anywhere near legal. This is especially the case where such changes of status quo contradict the 2016 arbitration ruling.

Assuming that China’s lawfare combines deliberate ambiguity surrounding its excessive claims and the enforcement of particularistic claims in the SCS,[23] it is still not clear what China’s lawfare has achieved in the legal domain in the last decade. It is often pointed out that the ambiguity of China’s claims, including its historic rights, is a deliberate policy choice that offers Beijing a degree of flexibility and room for manoeuvre.[24] Ambiguity about legal claims, the nature of disputes and the actors involved in disputes are certainly characteristic elements of grey zone challenges.[25] In this regard, ambiguity has been part of the attempt to maintain doubt about the excessiveness of China’s claim. This doubt, in turn, has served as a rhetorical cover for unilateral advancements of claims. While the exact scope and purpose of the ambiguity in China’s maritime claims may be debatable,[26] the arbitration ruling has put an end to the ambiguity about claims.[27] The ruling confirmed the Philippines’ point of view that China can only claim the normal entitlements under UNCLOS, which all other countries can also do.[28] The ruling established the types and the maximum extent of maritime zones that China can claim.[29] It thereby clarified that (i) if “historic rights” had existed, these “were superseded… by the limits of the maritime zones provided for by the Convention”;[30] (ii) no feature in the Spratly Islands or Scarborough Shoal can generate a claim to an EEZ or CS; and (iii) neither UNCLOS nor customary international law permits China to draw straight or archipelagic baselines around the Spratly Islands.[31] In other words, whatever the impression of plausibility regarding China’s maritime claims beyond the normal claims that may have resulted from China’s lawfare in the past, the arbitration ruling has put it to rest.

Importantly, this point is reflected in the growing international support for the arbitration ruling. Pre-ruling, 31 states objected to the arbitral tribunal’s jurisdiction or otherwise considered it to be illegitimate.[32] Yet, only six states have expressed opposition since the tribunal issued its award in 2016.[33] Crucially, there is a growing number of states officially backing substantive elements of the award in their respective Notes Verbales to the UN or in their public statements. These include the Philippines, Vietnam, Indonesia, the US, Australia, Malaysia, France, Germany, the UK, Japan, New Zealand and India.[34] As of today, only China objected to the tribunal’s jurisdiction and award in its Notes Verbales to the UN.[35]

These reactions from states around the world demonstrate that there is no general, established practice accepted as law that would allow China to claim historic rights and draw straight baselines around different groups of features in the SCS as its lawfare has tried to argue. On this issue of the law of the sea where China’s claims are in dispute with its neighbours and other maritime nations, China is no closer to promoting an alternative vision for the law of the sea than a decade ago. Not even the states that China mentions as objecting to the arbitration ruling argue that states can generally claim historic rights under international law. Moreover, while China and several other states defend a restrictive view on the scope of navigational freedoms of warships and innocent passage, there is no sign of coalition-building among these states.

The analysis does not imply, though, that China has not made lasting achievements in asserting its presence and control in the SCS. Land reclamation and the building of outposts have allowed China to increase the frequency and geographic reach of its naval and coast guard patrols in distant parts of the SCS. But this improvement in de facto reach of state power cannot be attributed to any conception of lawfare. Quite the opposite. The progress China has made on the ground is commensurate with the gap between China’s leadership aspirations and the distrust Southeast Asian elites have towards China. In the 2023 State of Southeast Asia Survey by the ISEAS – Yusof Ishak Institute, regional trust in China to maintain rules-based order and uphold international law was very low, at 5.3%, well behind the US (27.1%), the EU (23%), ASEAN (21%) and Japan (8.6%).[36]

That said, the response of members of the Association of Southeast Asian Nations (ASEAN) to China’s behaviour in the SCS remains ineffective. ASEAN-related fora are “strategically incompatible” to cope with the disputes.[37] Even Southeast Asian claimant states remain a fragmented mix. They do not share a strong consensus on precise and meaningful provisions for a code of conduct.[38] They lack a cohesive position on how envisioned regional ocean governance should be in line with the arbitration ruling. However, even where Southeast Asian responses to China’s activities remain underperforming, this cannot be attributed to China’s lawfare but to existing differences and disputes among Southeast Asian states as well as their cognition of the vast power asymmetry with China.

Despite years of lawfare in the SCS, China has not made gains in the legal domain. Traditional legal approaches to clarify the law, especially arbitration, have pulled away any legal cover that China’s lawfare in the SCS may have provided. What is left of China’s lawfare is the attempt to push through particularistic claims in contravention of the law of the sea as the arbitral tribunal and many states in the international community conceive it.


As the law of the sea is relatively well codified, at least in comparison to other international legal regimes, strategic interactions in the SCS take place “in the shadow” of the law of the sea. Analyses of the SCS disputes often use the term ‘lawfare’ to capture state choices surrounding the formulation of claims, the use of legal processes or naval operations that are subject to both legal and strategic considerations. Being used as a catch-all phrase for interactions between law and strategy in the SCS, this term obscures rather than reveals how the use of certain legal activities and processes is motivated by strategic considerations or how it can further them.

While China’s activities in the legal domain can be dubbed a lawfare strategy, China has not achieved much in the legal domain. To the contrary, traditional legal processes such as arbitration have resulted in a clarification of the applicable law, which pulled away any legal cover for changes of the status quo that lawfare may have provided. This is a lasting achievement of the South China Sea arbitration ruling. A good way to counter lawfare is the use of traditional legal processes. The fact that the ruling has witnessed increasing international support in the last few years lends credence to the idea that China’s lawfare in the SCS has been ineffective. Southeast Asian claimant states should build upon the momentum of the ruling by negotiating instruments of ocean governance in the SCS, i.e., fisheries management, marine protected areas and improved maritime law enforcement cooperation, that are consistent with and build upon the ruling. Consolidating the ruling in this way is certainly one avenue for countering China’s activities in the SCS.


For endnotes, please refer to the original pdf document.

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