The New Rules of Maritime Order
New Haven, Connecticut: Yale University Press, 2023, ISBN 9780300256475, 416 pp, RRP US$40.00
Author: Isaac B Kardon
Reviewed by: Samuel White
Isaac B Kardon’s China’s Law of the Sea: The New Rules of Maritime Order offers an insightful examination of China’s maritime ambitions and their implications for international maritime law. My own background is in the Australian Defence Force (ADF) (13 years across the permanent and reserve forces), and in my civilian employment I am an international lawyer and academic. This is not a particularly new area for me. However, Kardon’s analysis notably shifted my perspective on the complexity of the field and the flexibility of international relations, especially as it pertains to maritime governance, a subject of considerable importance as the ADF, Australia and many within the Indo-Pacific nervously eye events in the South China Sea.
Simply put, the book is structured into six substantive chapters. In Chapter 1 Kardon highlights how China is challenging traditional understandings of international law, and in Chapter 2 he outlines the relevant legal framework. The following four chapters are core reading for anyone trying to understand the key issues in the South China Sea. Kardon examines international legal principles as they apply in the following contexts: geographic (Chapter 3), resource (Chapter 4), navigation (Chapter 5) and dispute resolution (Chapter 6). These chapters are followed by a conclusion.
In framing the principles of international law, Kardon does not engage as heavily as one might expect with its Eurocentric nature, the history of its development as a corollary tool of colonisation and imperialism, or modern critiques of its structure.[1] These are important areas to cover in order to understand why Australia’s approach to a ‘global rules based order’ is not so readily received by other states within our region, let alone globally. To understand China’s motivations for critically engaging with the rules of international law, and questioning its application, requires consideration of its history, particularly its ‘century of humiliation’ (1839–1945). Kardon emphasises that China’s experience with foreign intervention and territorial losses during this period continues to shape its approach to international law. The emphasis on sovereignty and control over maritime space is not simply expansionist; it is deeply rooted in a historical narrative of vulnerability. Acknowledging this can provide a more nuanced understanding of Chinese actions in the South China Sea.
Instead of considering international law from the perspective of its European roots, Kardon posits that international law is binary in nature—developed and implemented either ‘top down’ or, alternatively, through ‘grassroots’ by states.[2] These two approaches to international law are simply put yet eye-opening. With this perspective, Kardon argues that China uses both methods concurrently not so much to break or change the rules as to reorder their importance. This unique standpoint provides a solid framework to engage with the contemporary debate of ‘Is China breaking the law of the sea?’.
One of the book’s strongest sections explores customary international law, with Kardon delving into its complex dual foundations in Chapter 2. Establishing that something (a rule, a principle, a crime etc.) is a matter of customary law depends on the satisfaction of two tests: state practice and opinio juris. Kardon illuminates the challenges these tests pose. State practice requires that countries act in a way that reflects a particular norm, consistently and over a significant period. As Kardon notes, the difficulty lies in identifying a genuine, consistent pattern of state behaviour. Countries may act with diverse motivations, and their actions are not always a straightforward reflection of legal obligation, making it tough to determine when a genuine customary norm has emerged. Opinio juris is the second requirement. It requires that a state act in a certain way in the belief that its actions are legally required, not simply as a matter of convenience. This element is especially difficult to prove. States may outwardly align with a practice but internally lack any belief that they are obligated to do so. In practice, opinio juris is challenging to measure, as states often keep their strategic reasoning private or justify deviations based on immediate needs rather than as an outright rejection of a norm. For those in the military legal field, Kardon’s analysis is a crucial reminder of just how intricate the process of establishing customary law is—and why it is so often contested.[3] Indeed, Kardon notes that customary international law is made through breaches of it.[4] This is not unique to international law and is reflected in the concept of critical legal theory that asserts that social friction drives law. Importantly, custom is the malleable part of international legal frameworks, making it the focus of strategic attention among states in grey-zone operations. A key strength of this monograph is its articulation of this concept.
Fundamentally, international law is implemented by states through their domestic law. In this regard, Kardon effectively highlights the Leninist approach to law as a tool.[5] In this model, law is explicitly and inescapably linked to party politics—law (international and domestic) should be used to promote party politics where it legitimises conduct, and distanced when it does not. China’s insistence on sovereign control over key ports and oceanic routes is, in many ways, comparable to Australia’s strategic imperatives to sovereign control over its maritime zones, as an island nation heavily reliant on secure maritime access. Reading Kardon’s account clarifies that China is hardly unique in strategically using treaties and international legal principles to secure national interests—a practice common to many nations.
In Chapter 5 Kardon dissects the ongoing debate over the nature of the United Nations Convention on the Law of the Sea (UNCLOS)—whether it serves as a ‘constitution for the oceans’ as some international lawyers believe, or merely a framework that states can interpret as they see fit. On the one hand, UNCLOS is black-letter law and is regarded by some lawyers as a constitution for the regulation of international maritime matters. On the other, the reviewer’s personal experience indicates that UNCLOS was intended to create a general framework only, with its architects hoping that subsequent treaties would develop in accordance with it.[6] Western nations, including Australia, largely subscribe to the notion of UNCLOS as a binding set of rules for maritime order.[7] By contrast, China views UNCLOS as a framework, interpreting its provisions to align with national strategies. Kardon highlights that this divergence in perspectives is not simply academic but has very real consequences for maritime stability in contested regions. For someone who has regularly worked within the framework of these laws (and continues to do so in the Indo-Pacific region), Kardon’s arguments compel reflection on the limits of standard assumptions about the stability of international legal systems. International law is often depicted as a stable framework, with clear rules defining states’ actions.[8] Yet Kardon exposes a much more dynamic, malleable reality, particularly when China not only violates and bypasses existing rules but also seeks to reshape them to serve its national interests. For those seeking to understand the critical area of controversy, Chapter 5 is significant. For those wanting to understand the full ambit of the complexity of the law of the sea, I recommend the book in its entirety.
Given the detailed nature of Kardon’s work, China’s Law of the Sea is a rigorous and eye-opening study but one that requires some commitment. This book offers dense reading for general practitioners in the profession of arms, with significant portions devoted to black-letter law. However, for those who can persevere through its technical aspects, it is a rare opportunity to see the world through the lens of the Chinese Communist Party and its approach to wielding law as a strategic tool. For staff officers in particular, Kardon’s analysis is invaluable. Understanding the roots of tension in maritime theatres and the legal frameworks surrounding these disputes is crucial. Equipped with the insights this book offers, staff officers can enhance their ability to seek nuanced assessments on aspects of international law from military and defence legal officers. In modern operations, where legal thresholds shape almost every decision, it is vital to understand our own legal frameworks and those of our military partners, as well as the legal perspectives of those nations with which Australia may find itself in competition. Kardon’s book equips military and strategic analysts alike with the context needed to interpret these frameworks and to anticipate how China may leverage them in future scenarios.
China’s Law of the Sea is more than an academic treatise; it is a critical resource that encourages practitioners to rethink the assumptions underpinning a Western understanding of maritime law. By challenging traditional perspectives, Kardon not only enriches the discourse but also equips military professionals with a deeper understanding of the evolving legal landscape. His work reminds us of the fluidity of international law and the role state practice plays in remoulding it, a reality that requires constant vigilance and adaptability.
Endnotes
[1] See Samuel White and Ikhwan Fazli, Pax Britannica: Tracing Customary War Crimes in the Age of Empire (Brill Nijhoff, 2025).
[2] Isaac B Kardon, China’s Law of the Sea: The New Rules of Maritime Order (New Haven CT: Yale University Press, 2023), p. 14.
[3] Ibid., p. 16.
[4] Ibid., p. 24.
[5] Ibid., p. 59.
[6] See for example the Underwater Cultural Heritage Convention, which expands upon UNCLOS Article 303.
[7] Natalie Klein, ‘Resolving Disputes under UNCLOS when the Coastal and User States are Disputed’, in Nong Hong and Gordon Houlden (eds.), Maritime Order and the Law in East Asia (Routledge 2019), pp. 19 – 32.
[8] Kardon, China’s Law of the Sea (n 2), p. 120.