Skip to main

AUKUS and the international rules-based order in the maritime domain

Context: the role of the rules-based order in the Indo-Pacific 

The idea of AUKUS began with the acquisition of strategic maritime capabilities: a partnership that would deliver nuclear-powered submarines to Australia. But if AUKUS is to be about more than sharing technology (“the what”), it needs to articulate a clearer common understanding of its deeper rationale (“the why”). Any answer to the question of why will involve a broad range of common values, concerns, and interests. This essay touches only on one part of that bigger picture: the importance of upholding the rules-based order in the maritime domain, especially in the Indo-Pacific.  

The last 15 years has seen the Indo-Pacific rediscovered, or perhaps re-invented, as a region. It is defined by vital sea lanes of communication (SLOCs) stretching from the Gulf of Aden and the Suez Canal through the Indian Ocean, the South China and Philippine Seas, and into the North Pacific. These SLOCs play a vital role in connecting major global economies such as India, China, Japan, and the United States as well as very large economies including Indonesia, South Korea, and Australia. The pivot for these sea lanes is the South China Sea, and it is in the South China Sea that different visions of international order come into sharpest relief. On the one hand, we see China advancing a series of legal, historical, and security arguments in favor of what seems to be a new regional maritime order, one centered on rules generated in Beijing. Meanwhile, AUKUS and other overlapping groupings, such as the Quad, pride themselves more on promoting the ostensibly universal rules-based international order (RBO). Even India, with its deep attachment to non-alignment, adopted the language of the rules-based order in 2015, adding credence to the claim the RBO is more than a Western construct.  

From an Australian perspective, we are comfortable with the idea of the RBO and, as a nation reliant on SLOCs, with its application to the maritime domain. In particular, we are eager to champion the UN Convention on the Law of the Sea (UNCLOS) as a central pillar of the maritime order. As the codified “constitution of the oceans,” UNCLOS is an easy thing to support; even the United States, not a party to UNCLOS as a treaty, accepts most of its rules as binding customary international law. However, the RBO is a slippery concept and potential false friend. It seems to encompass not just international law but also a series of political rules or assumptions about how international law and institutions should operate. To interlocutors in China and the developing world, this can sound perilously close to meaning: “the game of international law, played in a manner where the West always wins.” The danger in the term, then, is its potential to highlight any instances where we fall short of our own rule of law ideals. Our defense of UNCLOS needs to be clear and unambiguous, even if it involves confronting inconsistencies in our own conduct.  

We must also adopt a more sophisticated view of UNCLOS. While promoting adherence to UNCLOS may be the best path out of certain regional challenges, UNCLOS is also the source of a number of them, including the rise of coast guards as gray zone actors and in paving the way to maritime territorialisation (that is, treating maritime zones as if they were “blue national soil”). UNCLOS codified the concept of the exclusive economic zone (EEZ), giving coastal states 200 nautical miles (nm) of resource jurisdiction and control over what was previously the high seas. This created new economic opportunities as well as new opportunities for assertions of sovereignty. Law enforcement activities to regulate fisheries and other maritime resource extraction are significant assertions of sovereignty commonly conducted by white-hulled coast guard vessels. As a result, coast guards are increasingly on the frontline of strategic contestation. Coast guard operations are generally seen as less political or provocative than direct action by naval vessels in contested waters, which may lead to their increasingly aggressive use and unintended risks of escalation. In addition, the worldwide phenomenon of “creeping jurisdiction” in the EEZthe gradual assertion by coastal states of more numerous and extensive forms of sovereign authority in the zonehas led to its increasing assimilation to territory. That is, the EEZ was originally intended only as a zone of limited resource jurisdiction, but numerous states assert rights – for example, over the conduct of military activities – going far beyond what UNCLOS expressly allows. 

If AUKUS is concerned with upholding the RBO in the maritime domain, it needs to pay attention to efforts to upend or revise that order. Such efforts now most commonly occur below the level of direct clashes between conventional naval forces.  This may require a significant campaign of public diplomacy and lawfare (the use or misuse of law to achieve strategic objectives). We may also need to think about putting our own houses in order where our practice diverges from the strict adherence to UNCLOS that we preach. 

Challenges: the role of lawfare 

The fulcrum of the Indo-Pacific and its SLOCs is the South China Sea. Understandably, this has led to great focus on China’s efforts to construct its own regional order in its maritime “near abroad.” China understands the importance of lawfare in this process. Lawfare in the Chinese conception involves “leveraging of existing legal regimes and processes to constrain adversary behavior, contest disadvantageous circumstances, confuse legal precedent, and maximize advantage in situations related to the PRC’s core interests.” To this end, China has engaged in a campaign of island building; flooded the South China Sea with its over-capacity fishing fleet and asserted the exclusive right to regulate fishing throughout those waters (including imposing fishing moratoria); and attempted to shift legal norms to legitimate its claims to all waters inside the so-called “nine-dash line.”  

Such efforts first require asserting or establishing control over contested waters. Much of the focus of analysts has been on the Chinese maritime militia, specially equipped fishing vessels staffed by People’s Liberation Army Navy (PLAN) reservists capable of being called up to support navy operations. This has made the militia a classic “gray zone” actor capable of carrying out operations below the level of conventional conflict. The maritime militia also carry out a form of lawfare through their ambiguous status; other claimant states in the South China Sea cannot tell if engaging ostensible fishermen may trigger a military response. Beyond this, the China Coast Guard (CCG) is playing an increasingly important and assertive role in a space between the maritime militia and the PLAN.  

The CCG appears constructed to blur distinctions between a maritime militia and an official naval force. It has rapidly grown since its creation in 2010, when five different maritime agencies were consolidated into one. In the year since, it has swelled from 156 to 524 patrol vessels. Some of these craft are 12,000-ton vessels built on the scale of frigates. The CCG easily outmatches most regional navies. It has been given a broad and ambiguous mandate under the 2021 Chinese Coast Guard Law to operate throughout “waters under Chinese jurisdiction” without defining where those waters are or how they relate to UNCLOS concepts such as the EEZ. This has raised concerns that the law is intended as a strategic signal that the CCG is authorized to use force throughout the South China Sea to defend China’s claims. If this view is correct, then the law exists as part of a wider campaign to consolidate effective control in the South China Sea. (Arguably, a lesson China first learned from Japan’s use of coast guard vessels to defend claims to the Senkaku Islands.) 

Regardless, the 2021 Chinese Coast Guard Law highlights the uncertainties surrounding China’s legal conception of the South China Sea. Under UNCLOS, a coastal state does not have sovereignty over waters beyond a 12-nautical-mile territorial sea. Beyond that, one has only limited “sovereign rights” to explore and exploit the EEZ out to 200 nautical miles and the continental shelf (which may extend further).  

Arguments that China has special historic rights to exploit and regulate natural resources throughout the South China Seathough not to interfere with foreign navigationwere comprehensively rejected by the arbitral tribunal convened under UNCLOS in the Philippines v China dispute. This was on the basis that the historic rights claimed by China were incompatible with UNCLOS. The tribunal also disposed with the possible alternative argument that China had sovereignty over a series of islands throughout the South China Sea, each capable of generating its own extensive EEZ. On this point the tribunal ruled that most of the features in question were incapable of human habitation and economic activity without substantial external support, meaning they were not “islands” in law but only “rocks,” the difference being that only an island generates an EEZ; rocks have only a 12 nm territorial sea.  

This leaves us with the muddled situation where Chinese national law attempts to supplant UNCLOS concepts of defined maritime zones with the nebulous concept of waters “under Chinese jurisdiction.” This could be a step in a deliberate process of territorialisation, changing the effective status of the South China Sea through a multi-layered process of establishing facts on the ground (literally, in the case of island-building), manufacturing legal ambiguity, and deploying public narratives. This would be consistent with statements in Chinese policy documents that the waters of the South China Sea represent “blue national soil.” Applying the language of sovereignty to maritime spaces as if they “were subject to sovereignty applied ‘fully and flatly’ within clearly demarcated borders” is potentially alarming. It is hard to judge where a competitor’s red lines are if their underlying claims cannot be clearly articulated. And for better or worse, international law is the best language we have for states to articulate their claims in a mutually comprehensible manner. 

Public diplomacy and counter-lawfare 

Countering China’s efforts to subvert the laws of the seas could be as simple as demanding strict adherence to the existing, documented rules of law. However, the AUKUS states are not always well-positioned to do this. As a non-party to UNCLOS, the United States will always face a credibility gap when invoking the treaty. It is a gap not fully covered by U.S. assertions that it accepts most of the rules of UNCLOS as binding international law while remaining outside UNCLOS’ binding arbitration system. Australia, for its part, has its own difficulties in invoking the 2016 ruling. The tribunal took a very narrow view of what constitutes an island entitled to an EEZ. Australia’s Antarctic territories of the Heard and McDonald Islands almost certainly fail this test, but Australia shows no signs of relinquishing their valuable 200 nm EEZs. Finally, the United Kingdom draws a rather eccentric series of straight baselines around the Falkland Islands (see map 13 here). The point might seem too arcane to warrant concern, but China has invoked this precedent in justifying some of its practices in the South China Sea. 

AUKUS has the opportunity to be a unifying force in defence of the maritime RBO, but only if its members are able to adopt a common position on critical issues and demonstrate commitment to UNCLOS in deed as well as word. To be convincing defenders of UNCLOS and the RBO in the maritime domain, we need to be clear-eyed about getting our houses in order. We must also be sensitive to the distinction between states like China, which seek to create new rights not recognized by UNCLOS, and Pacific Island states threatened by sea-level rise, which are currently campaigning to keep their maritime zones even as they begin to lose the land that historically generated them. The idea that a degree of legal creativity is warranted to preserve the maritime status quo for nations existentially threatened by climate change is one we should welcome and support. But avoiding the charge that Western powers pick and choose when UNCLOS is up for re-interpretation may be harder. Nonetheless, the legal battlespace is an increasingly important domain of ‘grey zone’ conflict and one in which China has shown increasing capabilities. It is not a domain we should cede. This is not merely a question of principle. Law defines who owns what. Support for the RBO is crucial if states under pressure in the South China Sea are to maintain their entitlement to their own EEZs. 

About the Author

Douglas Guilfoyle

Douglas Guilfoyle is Professor of international law and security at the University of New South Wales Canberra. His principal areas of research are maritime security, the international law of the sea, and international and transnational criminal law. He has published widely on maritime law enforcement, the law of naval warfare, international courts and tribunals, and the history of international law. His research work is informed by his consultancy to various government and international organisations. He is currently a Australian Research Council Future Fellow, working on the project “Small States’ use of law of the sea litigation against greater powers”. He was previously a Visiting Legal Fellow at the Australian Department of Foreign Affairs and Trade, a Professor of Law at Monash University and a Reader in Law at University College London. He was a Gates Cambridge Trust scholar and Chevening scholar during his graduate study at the University of Cambridge.


Security & Defence PLuS Research and Articles

What AUKUS means to Britain: Appraising the Benefits and Challenges in an Election Year

By and

10 April 2024 In March 2024, British premier Rishi Sunak declared a “national endeavour” with a new fund to “secure...

AUKUS and the Potential for a Disruptive Maritime Power


In April 2023, the Australian government released its Defence Strategic Review, setting out a vision for reforming the country’s national...

To Exclude or Not to Exclude: AUKUS and Order-Engineering

By and

Introduction While the delivery aspect of AUKUS – that is of nuclear-propelled submarines and advanced technological capabilities – continues to...