Chief Justice Sundaresh Menon: Keynote Address at the International Law Association (Singapore Branch) Symposium 2025

1.    A very good afternoon. I am honoured to address this year’s Symposium. I am especially pleased to join you in celebrating the 10th anniversary of the ILA-SG, since I had a small part to play in seeding the idea of its establishment. My friend and judicial colleague, Lord Mance, who was Chairman of the Executive Council of the International Law Association at the time, had raised the possibility of founding a Singapore branch. Having long been a believer in the necessity for and importance of international law, and in strengthening its institutions, I gently nudged my colleagues at the Attorney-General’s Chambers in this direction, and it received an enthusiastic response. Lord Mance and I both spoke at the launch of the ILA-SG ten years ago and it is a special privilege for me to be back today. The last decade has shown that even as international law has come under extraordinary pressure, that has only highlighted its importance and the vital necessity for all of us, whose life and work is in the law, to devote ourselves to protecting, strengthening and enhancing its vitality and its ability to order our world. Yet, how so, it might fairly be asked, in the light of the impunity with which those the law is intended to reach, are seemingly able to ignore it? 

2.    To contextualise this, let me bring you to February 2024, when the International Court of Justice convened hearings on Israel’s activities in the Occupied Palestinian Territory. Over six days, the World Court received oral statements from more than fifty states and international organisations – an unprecedented number in the court’s nearly 80-year history.⁽¹⁾ In a landmark advisory opinion, the court determined that Israel’s continued presence in the Occupied Palestinian Territory was unlawful, that it was obliged to bring this to an end, and that all states were obliged not to recognise this situation as legal and not to render aid or assistance in its maintenance.⁽²⁾ The General Assembly welcomed the opinion and demanded that Israel end its unlawful presence without delay and within 12 months in any event.⁽³⁾

3.    One might think that this was a resounding victory for those who moved the court, and concrete evidence of the international community’s unwavering faith in and reliance upon international law and its institutions.⁽⁴⁾  Yet, as one law minister who participated in the proceedings observed to The Guardian newspaper, “there was an acute realisation [among colleagues] that none of this [was] actually going to change anything on the ground”. His own, rather stark assessment was that civilians will remain “caught up in [a] web of geopolitics that is not of their own making”, and that “[n]o matter which court you approach, you are not going to get justice”.⁽⁵⁾

4.    Those words, spoken not by a cynic but by a lawyer engaged with the very system he was critiquing, highlight the evident yawning divide between our vision for international law and its lived realities. And for me as a judge, and I dare say for many, if not all, of us who are interested in the project of international law, this dissonance is deeply unsettling. Courts exist precisely to dispense justice, and the law is meant to serve the common good by affording a framework for resolving differences fairly in the real world. It may be that ICJ advisory opinions and General Assembly resolutions are of limited legal effect, but even so, the seemingly indifferent disregard for them raises serious questions about the state of the international legal order.

5.    The rules-based international order which emerged from the ashes of the Second World War has been a bulwark against geopolitical upheaval and the bedrock for what has been a prolonged period of relative peace, free trade, and unparalleled prosperity. Yet with the geopolitical turbulence witnessed in recent years, it can often feel as though the world as we know it might be headed for a reset of some sort. Indeed, the very future of the international rule of law has become a defining issue of our time, which is surprising given that most of us would have found this unthinkable just a decade ago.

6.    This afternoon, I will propose that despite the gloom, the international community should not lose hope in international law and its institutions, and should instead renew and strengthen its commitment to the rules-based international order and to the international rule of law. I will develop this thesis by considering four questions:

(a) first, what the rules-based international order is;

(b) second, what threats it faces; 

(c) third, why we need to act; and 

(d) lastly, how we might chart the way forward.

I. The foundations of the rules-based international order

7.    Let me begin with the foundations of the rules-based international order. In 1979, Professor Louis Henkin famously asserted that “almost all nations observe almost all principles of international law and almost all of their obligations almost all of the time”.⁽⁶⁾ To the extent it is true, that is a remarkable record, especially when one considers the many criticisms that have been levelled against international law over the years – both as a system of rules and also in terms of the reality of its shortcomings. It does not have a central legislature, or courts with compulsory and universal jurisdiction, or a transnational police force with effective enforcement powers.  International law must instead typically rely on other things to secure a measure of compliance, such as the perceived value of international cooperation, the legitimacy of international institutions, and above all, a shared commitment to the international rule of law.⁽⁸⁾ 

8.    These are the very things that underpin the rules-based international order as it exists today. Drawing inspiration from the work of Professors Monica Hakimi and Jacob Cogan, I suggest that the rules-based international order can be understood as having five core features:⁽⁹⁾ 

(a) First, the order engenders a commitment to deeper legalisation, where the law represents the dominant mode of interaction between states. States assert legal norms to regulate conduct, invoke legal procedures to resolve conflicts, and conclude agreements using familiar legal structures to deepen cooperation and to signal policy commitments. 

(b) Second, the rules-based order embraces a statist model. Sovereign states constitute its primary actors and lawmakers. Their autonomy and authority are safeguarded through foundational principles, such as sovereign equality and the prohibition on aggression.

(c) Third, there is a commitment to the work of international institutions. In the legal landscape, institutions provide the highways and marketplaces for cooperation and exchange. States benefit from a latticework of forums for negotiation and decision-making, hubs for the distribution of aid and assistance, and centres of research and expertise. 

(d) Fourth, the rules-based order promotes the expansive regulation of human activity, both across borders and increasingly within the domestic sphere. Its field of concern has been enlarged to cover a range of non-state actors, from foreign investors to terrorist groups.⁽¹⁰⁾ 

(e) Finally, what anchors all of these features is the international rule of law. This encapsulates a global compact where states commit to using the law to regulate their affairs and to address their differences, in preference to the arbitrary or unbridled exercise of power. This commitment does not mean forsaking pragmatic interests altogether under some utopian ideal. Rather, it entails pursuing these interests within a principled framework, with the understanding that this commitment represents the only credible way of ensuring that the exercise of state autonomy does not imperil the common good.⁽¹¹⁾ 

9.    These features of the rules-based order might seem axiomatic, especially to international lawyers. Yet, this model of international law is neither self-actualising nor guaranteed. As history demonstrates, it was a hard-earned, hard-won consequence of the post-World War II settlement.

10.    It took two immensely tragic world wars, and the false dawn of the League of Nations and the Kellogg-Briand Pact, before the use of force was definitively outlawed as an instrument of national policy in 1945.⁽¹²⁾  This subordination of might to right has been hailed as one of humanity’s greatest achievements in the 20th century and even as representing a new “civilisational consensus”.⁽¹³⁾  It finds expression in Article 2(4) of the UN Charter where it sits alongside other quasi-constitutional principles such as the sovereign equality of states and the peaceful settlement of disputes. The Charter’s preamble reinforces this ambition with its solemn reminder that the United Nations was established with the noble aim of “sav[ing] succeeding generations from the scourge of war”, and “reaffirm[ing] faith … in the equal rights of … nations large and small”, at a time when none of this could be taken for granted.⁽¹⁴⁾ 

11.    A second historic milestone was the Nuremberg trials, which ushered in a new age of international criminal justice. As Nuremberg prosecutor Justice Robert Jackson declared in his opening statement, the trials represented “mankind’s desperate effort to apply the discipline of the law to statesmen who have used their powers of state to attack the foundations of the world’s peace and to commit aggression against the rights of their neighbours”. 

12.    The trials played an instrumental role in promoting the legitimacy of the new international order. Victor’s justice was administered through criminal trials with due process rather than through summary executions.⁽¹⁵⁾  At the same time, the Nuremberg principles significantly advanced the project of ending criminal impunity, by emphasising individual accountability regardless of one’s rank or status, and by affirming that a state’s domestic law afforded no defence to internationally-recognised crimes. ⁽¹⁶⁾

13.    A third pillar of the post-war transformation was the global financial architecture forged at the Bretton Woods conference. An enhanced multilateral system replaced the inward-looking, isolationist and beggar-thy-neighbour policies that had been a significant cause of the Second World War.⁽¹⁷⁾ Under this blueprint, the International Bank for Reconstruction and Development would finance postwar recovery efforts, while the International Monetary Fund was entrusted with promoting monetary stability through a new framework for currency convertibility. And although the International Trade Organisation never came into being, the General Agreement on Tariffs and Trade advanced the agenda of trade liberalisation and significantly dampened the protectionist tendencies that had characterised the prewar period.

14.    What followed these watershed events was a period of active treaty-making that spurred the proliferation and thickening of international legal norms, across areas as diverse as human security, economic integration and human rights. In 1964, Professor Wolfgang Friedman observed that this was not merely a change of degree but of kind – that international law was evolving from a law of coexistence to one of cooperation. This captures the feel of the moment – the transformation of international law’s priorities from the securing of negative peace to the pursuit of the collective good.⁽¹⁸⁾ Alongside this shift, the General Assembly adopted the Friendly Relations Declaration by consensus in 1970, marking the 25th anniversary of the United Nations. This reaffirmed that seven Charter-based principles had become cornerstones of international society. ⁽¹⁹⁾

II. The rules-based international order under pressure

15.    For all its imperfections, the rules-based order supported a remarkable period of “long peace” and relative prosperity. When I delivered the S Rajaratnam Lecture in 2019, I suggested that while the international rule of law had come under great strain on several occasions – sometimes, it seemed, almost to breaking point – one could say with confidence that it remained alive and well. ⁽²⁰⁾  Indeed, the first two decades of the 21st century have been punctuated by several flashpoints that have tested the limits of international law, from 9/11 to the Syrian civil war. Even so, and even as the world continued to make uneven progress on wicked problems such as climate change, the fundamental architecture of the rules-based order proved remarkably resilient.

16.    With the events of the past six years, however, there is a sense that the tide has shifted, and that as it recedes, it has left exposed the fragility of the foundations that lie beneath the surface.

17.    The Covid-19 pandemic posed the first major test of this decade, and indeed, one of the most far-reaching and disruptive events to confront humanity over the last century. When it was upon us, we witnessed the swift retreat of states behind their borders, as many traded collective solidarity for national preservation.⁽²¹⁾ With over seven million reported Covid-19 deaths worldwide,⁽²²⁾ those dark days are a poignant reminder of humanity’s shared vulnerability and our profound interdependence. 

18.    But while the pandemic illustrates the international system failing to work as intended, we now confront a drumbeat of developments that threaten to undermine and perhaps even dismantle the rules-based international order in fundamental ways. The mood of the moment was captured by Secretary-General António Guterres in an address to the General Assembly in 2022, when he warned that the UN Charter and its ideals are in jeopardy, that the international community is “gridlocked in colossal global dysfunction”, and that a “winter of global discontent” is on the horizon.⁽²³⁾  A number of developments could illustrate this troubling trajectory, but allow me to focus on two in particular: the war in Ukraine and the evolution of US foreign and trade policies.

A. Russia’s invasion of Ukraine

19.    Russia’s invasion of Ukraine has been described as the most significant shock to the international order since World War II.⁽²⁴⁾ Russia has drawn widespread condemnation for its flagrant violation of the prohibition on the use of force.⁽²⁵⁾  In 2022, our Foreign Minister Dr Vivian Balakrishnan delivered a ministerial statement describing Russia’s conduct as a “clear and gross violation of international norms” and an “existential issue” for our nation.⁽²⁶⁾  He explained that if states could be attacked simply because aggressors deemed their independence illegitimate, this would “go against the internationally recognised legitimacy and territorial integrity of many countries, including Singapore”.⁽²⁷⁾ 

20.    Some suggest that Russia’s conduct is especially dangerous because of its colourable use of the language of international law to cloak its violations with a veneer of legitimacy.⁽²⁸⁾  Of course, the ICJ has observed in its 1986 Nicaragua decision that where a state justifies its conduct by appealing to exceptions or justifications contained within a legal rule, this tends to confirm rather than weaken the rule.⁽²⁹⁾  But this cannot be the case where the proffered justifications do not have any reasonable basis. And, scholars have commented that Russia’s apparent justifications appear to apply commonly-agreed concepts in “peculiar” and even “cynical” ways, leading some to suggest that it is using the law as a weapon of war or “lawfare”.⁽³⁰⁾ 

21.    Professor Marc Weller, Chair of International Law and International Constitutional Studies at the University of Cambridge, has argued that none of Russia’s justifications stand up to scrutiny:⁽³¹⁾ 

(a) First, there was no humanitarian emergency that would trigger the doctrine of humanitarian intervention.

(b) Second, Russia was not answering a request for collective self-defence from the separatist Republics of Luhansk and Donetsk. In fact, even as a threshold matter, these territories could not invoke the doctrine because they are not states.⁽³²⁾ 

(c) Third, Russia was not defending the people of Ukraine, nor was Russia defending itself from Ukraine. There is no evidence of Ukraine acquiring nuclear weapons or developing biological weapons, while the notion that Russia had to respond to NATO’s presence in Ukraine distorts the doctrine of self-defence.

22.    Professor Weller thus concludes that Russia’s “perversion of both the facts and the law” has moved its reasoning beyond the realm of standard legal discourse.⁽³³⁾  In other words, we are dealing with a challenge of “alternative facts”, being deployed to mask or divert attention from a basic violation of international law.

23.    Apart from the lack of any basis for Russia’s invasion, the credibility of the rules-based international order is being further strained by the seemingly intractable difficulty of ending the war. Negotiating an end to any conflict is a complicated exercise in diplomacy even at the best of times, but here the challenge is compounded by Russia’s veto power in the Security Council.⁽³⁴⁾ 

24.    It is true that criticisms surrounding the veto do not only apply to Russia. It is also true that the veto system is the product of a historical compromise: the US and USSR made veto power a condition for joining the UN, and the veto system arguably represents an improvement over the League of Nations’ requirement of unanimity.⁽³⁵⁾ But the veto system’s effects on conflict resolution are difficult to ignore. Between 1945 and 1992, the P5 states exercised the veto 279 times in relation to intervention in armed conflict – a period which saw over 100 major conflicts and some 20 million casualties.⁽³⁶⁾ The picture was particularly bleak during the Cold War, when the Security Council became the centre stage for ideological battles between the East and the West.⁽³⁷⁾ Unsurprisingly, the veto system has become a lightning rod for criticism of the United Nations.

B. US foreign and trade policies

25.    Moving across the Atlantic, the rules-based international order has come under further strain from fundamental shifts in US foreign and trade policies. This January, Secretary of State Marco Rubio declared that “[t]he post-war global order is not just obsolete, it is now a weapon being used against [the United States]”.⁽³⁸⁾ This signalled a marked departure from the historical role of the United States as a key architect of the post-war system and its foremost champion and defender.⁽³⁹⁾ 

26.    The rules-based international order thus faces a vacuum. The US has long been the UN’s largest financial contributor, providing 22% of its core budget and 27% of its peacekeeping budget according to recent figures.⁽⁴⁰⁾ Now, it has initiated a comprehensive review of all multilateral organisations and treaties to which it is party.⁽⁴¹⁾ It has already notified its withdrawal from the 195-party Paris Agreement and the 194-member World Health Organisation (which will both take effect in January 2026).⁽⁴²⁾  For those institutions that the United States decides to remain in, some observers expect it to pursue a “back-to-basics” agenda that will refocus such institutions on their founding principles,⁽⁴³⁾ thus potentially narrowing the scope of their work. The US has also continued to exert influence on other institutions it is not a member of but whose actions it deems unsatisfactory, for instance, by imposing sanctions on judges and prosecutors of the International Criminal Court.⁽⁴⁴⁾ 

27.    This turn from multilateral engagement is also apparent in US trade policy, with its current focus on power-based bargaining backed by the threat of tariff escalation.⁽⁴⁵⁾ In his ministerial statement in response to the US tariffs and its implications in April this year, Prime Minister Lawrence Wong noted that the US’s new tariff regime was incompatible with the most-favoured nation (MFN) principle that underpins the WTO system, and that it opened the door to “selective country-by-country trade relationships, based on unilateral preferences”.⁽⁴⁶⁾ While the worst of the tariffs have not come to pass for Singapore, the dust has not settled and it may never truly settle – and that is precisely the concern. Trading relationships are far less predictable than they once were, without the certainty and stability that the WTO system was meant to provide.⁽⁴⁷⁾  As PM Wong reiterated at this year’s National Day Rally, it is “little comfort” to a small and open economy like Singapore that it is subject to the baseline 10% tariff rate, because that baseline can shift and higher tariffs can still be set for specific industries.⁽⁴⁸⁾  What these developments point to, I suggest, is a much deeper concern: are we about to witness an international order where the international rule of law is no longer its anchor?

III. The rules-based international order as an existential necessity

28.    These developments are a salient and urgent reminder that nothing about the present international order is assured, and that even a tiny prospect that it might one day come apart at the seams should give all of us cause for pause. This is because the rules-based order represents the only hope we have to develop credible and effective answers to many of our most pressing problems and needs.⁽⁴⁹⁾ In other words, I suggest that the rules-based order is today an existential necessity for humanity, and I suggest that there are at least three reasons for this. 

29.    First, most states depend on international law literally for their very existence. International law is the only system of law that can meaningfully regulate inter-state relations, and the post-war rules-based order is the only conception of international law that is committed to securing the territorial integrity, political independence and self-determination of all states and the peaceful resolution of disputes.⁽⁵⁰⁾ When the UN was established in 1945, nearly a third of the world’s population still lived in territories that were not self-governing. That figure today stands at fewer than two million people, following the end of empire and the resulting birth of more than 80 newly-independent nation-states.⁽⁵¹⁾  Without the rules-based order, we risk a return, over the long term, to a loss of the right to self-determination and the end of colonialism, when these have been accepted in the post-war era as foundational elements of the law of international relations and inalienable rights of humanity.

30.    This reality weighs especially heavily on small states, which, as Ambassador Tommy Koh recently observed, rely on international law as both their sword and shield.⁽⁵²⁾  To appreciate this point, we need only recall the iconic Melian dialogue from 416 BCE, when Athenian forces invaded the small and neutral island of Melos. When the leaders of Melos appealed to justice to resist the invasion, the Athenian forces dismissed their plea with the stark declaration that “the question of justice only enters where there is equal power to enforce it … the powerful exact what they can, and the weak grant what they must”.⁽⁵³⁾ This alternative – of a brutal world where might makes right – would not only be arbitrary and unjust, it would be fundamentally corrosive to human dignity. And if this fails to cut ice with the powerful of the day, history tells us that no power has ever remained invulnerable. What goes around, eventually comes around.

31.    Second, humanity needs the rules-based international order to tackle the gathering storm of challenges that confront us all.⁽⁵⁴⁾ The scale of these challenges is sobering:

(a) For one, greenhouse gas concentrations continue to reach record highs each year. By 2023, carbon dioxide levels were already 150% above pre-industrial levels.⁽⁵⁵⁾ Some 3.3 to 3.6 billion people live in areas that are highly susceptible to the effects of climate change, and some 250,000 additional deaths due to climate change are expected each year between 2030 and 2050.⁽⁵⁶⁾  Closely linked to this is the ever-looming threat of the next global pandemic. One recent EU study suggests that nearly 10% of the global land surface is at high or very high risk of disease outbreaks, such as Ebola and Zika.⁽⁵⁷⁾  

(b) Global forced displacement is also at an all-time high. As of May 2023, more than 110 million people have been forced to flee persecution, violence or human rights violations.⁽⁵⁸⁾ The refugee population alone has doubled since 2015 to almost 36 million.⁽⁵⁹⁾ This is symptomatic of the slow progress made on the UN Sustainable Development Goals more generally. Since 2015, progress on a third of its 135 targets has either stalled (18%) or regressed (17%), and the world is on track to achieve only 17% of them by 2030.⁽⁶⁰⁾ 

(c) And, on top of this, rapid advancements in AI systems have also introduced a host of new challenges for human accountability, cybersecurity and grey zone warfare, leading the General Assembly to pass some of its first resolutions on AI last year.⁽⁶¹⁾ 

32.    We are all vulnerable to these challenges to varying degrees, but their intractable and polycentric nature means that they can only be solved or approached through a collaborative and transnational effort.⁽⁶²⁾ Indeed, many of these challenges concern the coordination of global public goods that cannot be fully controlled, produced or regulated by any single state.⁽⁶³⁾ 

33.    These shared challenges underscore the need for robust international institutions. As Professor Harold Koh puts it, the very function of international organisations is to “organise proactive assaults on all manner of global problems” and to elevate systemic concerns over parochial interests.⁽⁶⁴⁾ Indeed, among their greatest strengths are their convening power and their remarkable ability to keep critical issues on the global agenda for decades.⁽⁶⁵⁾ Equally important is the agency that they give to small states.

34.    A third reason for the rules-based international order is that in many cases, international institutions alone can realistically offer solutions that display staying power and that command greater legitimacy than purely national responses. This is especially true of third-party dispute resolution.⁽⁶⁶⁾ Taking the case of Russian aggression as an example, while it is no doubt possible for the Ukrainian courts to prosecute perpetrators (as they have done), there can be challenges in terms of capacity, expertise, and above all, perceived independence.⁽⁶⁷⁾ It would be difficult for such proceedings to “escape the taint of victor’s justice or, as the case may be, victim’s revenge”.⁽⁶⁸⁾ 

IV. Revitalising the rules-based international order

35.    For all these reasons, the rules-based international order is now, perhaps more than ever before, an existential necessity for all of mankind, but also one that is increasingly under threat. The question that confronts us is: where do we go from here?

36.    The views of international lawyers are as varied as they are revealing. As an article in The Guardian memorably observed, “[i]nternational lawyers are … divided over whether their discipline is alive and well, in hibernation, in its death throes, or long deceased, a ‘moral ghost’ that hovers over the world map”.⁽⁶⁹⁾ For example, Sir Daniel Bethlehem, a former legal advisor to the UK Foreign Office, has described our postwar institutions as “sclero[tic]” and unfit for purpose, and has prescribed a course of radical reimagination.⁽⁷⁰⁾ On the other hand, Judge Dire Tladi of the ICJ suggests that what we are facing is a failure not of international law, but international politics.⁽⁷¹⁾ Either way, it is in need of urgent help.

37.    I begin with the proposition that the international community cannot afford to jettison the rules-based international order. There is much we have achieved with the present system that should be jealously guarded, such as the widely (and, until recently, I would have said universally) accepted prohibition on the use of force.⁽⁷²⁾ At the same time, it may be unduly sanguine to treat recent developments as just an aberration that will in time leave the international order fundamentally unscathed.

38.    I suggest instead that what we need is a spirit of sober optimism – one that recognises the immense value of the wider project of international law, without subscribing dogmatically to all of its ideas. Translating this spirit into action demands that we pursue two key imperatives: we must vigorously defend and affirm the international rule of law, but we must also honestly confront the weaknesses that have eroded faith in the rules-based order. Let me elaborate on each of these.

A. Affirming the international rule of law 

39.    First, it is crucial that states fiercely defend the primacy of the international rule of law, and take a united stand in calling out and condemning violations of its cardinal norms. It is precisely when faith in the rules-based order is backsliding in some quarters, that it requires our most resolute defence.⁽⁷³⁾ 

40.    This commitment is essential not because it will somehow miraculously restore compliance with international law in every case, but rather, because the international rule of law is only as strong and as visible as we choose to make it. As the late James Crawford pithily observed in his Hague Academy lectures, a preoccupation with the effectiveness or enforceability of international law “reduces law to the length of the policeman’s truncheon and misrepresents the complexity of the reasons we have law and the plurality of the purposes law serves”.⁽⁷⁴⁾ We must not lose sight of the important constitutive and norm-building effect of the law, and the role that state practice plays in shaping these norms. It is the normativity of the law that will ultimately pave the way for compliance, and in more extreme situations, enforcement.⁽⁷⁵⁾ 

41.    We should thus be encouraged by how a significant majority of states have registered and reiterated their concern over developments in Ukraine and Gaza, with many mobilising resources to uphold fundamental norms. An overwhelming 141 states “deplor[ed]” Russia’s violation of the UN Charter “in the strongest terms” in an emergency General Assembly session – only the eleventh such session since 1950.⁽⁷⁶⁾ This had been matched by a host of tangible measures, from military assistance to criminal prosecution.⁽⁷⁷⁾ In the case of Gaza, the General Assembly has also adopted two resolutions that sought advisory opinions from the ICJ, including on Israel’s obligations under international law in relation to the Occupied Palestinian Territory.⁽⁷⁸⁾  

42.    Another noteworthy development is the launch of the “Global Initiative to Galvanise Political Commitment to International Humanitarian Law”. This was pursued by the International Committee of the Red Cross and a geographically diverse group of states, including Brazil, China, France and South Africa. The goal is not to develop a new convention, but to ensure that international humanitarian law commands the political attention it deserves when conflicts erupt, and to foster dialogue on persistent challenges such as the prevention of violations. This is expected to culminate in a landmark meeting on upholding humanity in war in 2026.⁽⁷⁹⁾ 

43.    Apart from denouncing violations of international law, states should positively intensify their engagement with international institutions and processes. This is especially for institutions like the UN, which, as Minister Vivian Balakrishnan highlighted in a recent interview, is “the only game in town” that can bring all states together.⁽⁸⁰⁾ The recent momentum achieved in the area of climate justice exemplifies the value of deepened engagement. Over the past two years alone, the European Court of Human Rights,⁽⁸¹⁾ the International Tribunal for the Law of the Sea,⁽⁸²⁾ and the Inter-American Court of Human Rights⁽⁸³⁾ have all issued significant rulings that not only recognise but emphatically reinforce the obligations of states to mitigate and to respond to climate change. Most recently, in a rare unanimous opinion, the ICJ ruled that climate inaction can fully engage the responsibility of states through a constellation of obligations.⁽⁸⁴⁾  Remarkably, these proceedings saw the participation of nearly a hundred states and a dozen international organisations. And the genesis of the case is equally striking: what initially began as a university project by Vanuatu students to explore pathways for climate action eventually crystallised in the UN resolution that requested the Court’s opinion, which commanded the support of more than 130 states, including Singapore.⁽⁸⁵⁾ 

44.    That last point highlights how international lawyers and civil society, too, bear an equally weighty responsibility in our shared endeavour to uphold the international rule of law. International lawyers have historically made significant contributions as honest brokers and constructive interlocutors in even the most challenging of conflicts. Through sustained advocacy, they shape the very discourse through which international norms evolve and to which states are held to account.⁽⁸⁶⁾

45.    This proud tradition of consensus-building and principled engagement runs deep in the DNA of international lawyers in Singapore, who have led and served with distinction in various forums, from United Nations committees to UNCITRAL Working Groups. We count in our ranks distinguished lawyer-diplomats such as Ambassadors Tommy Koh and Rena Lee, who have respectively been referred to as the “midwife” of the United Nations Convention on the Law of the Sea, and the “mother” of the BBNJ, or the Agreement on Marine Biological Diversity of Areas Beyond National Jurisdiction.⁽⁸⁷⁾ Both ambassadors played a pivotal role in bridging vast differences between states, and in securing the conclusion of groundbreaking treaties that concern crucial aspects of our global commons. It is thus a matter of national pride that Singapore has nominated Ambassador Lee for election as an ICJ Judge in 2026. She is the very first Singaporean to be nominated since Singapore joined the UN in 1965, and if elected, will be only the second person from Southeast Asia to serve on the World Court.⁽⁸⁸⁾ 

46.    This tradition also sustains the important work of the ILA-Singapore in fostering understanding of, and respect for, international law. Since its establishment, it has matured into a diverse body of more than 140 members, making it one of the largest local chapters of the ILA. As a sign of its continuing evolution, it also welcomed a student chapter last year.⁽⁸⁹⁾ Its annual symposium brings together the community of international lawyers in Singapore, and offers a safe and constructive environment for having frank discussions on difficult issues of international law. Another timely development within the wider umbrella of the ILA is the creation of a new study group on the rule of law in international relations, which has been tasked with developing “a more coherent and persuasive basis for the concept and authority of the rule of law”.⁽⁹⁰⁾

B. Acknowledging the weaknesses of the international legal order

47.    But a commitment to the rules-based order does not entail uncritical acceptance of all of its features, however flawed they may be. Such an approach would only erode the legitimacy of the international order. As our Foreign Minister again observed when he delivered Singapore’s national statement to the UN General Assembly two weeks ago, “[t]he current distribution of economic weight, technological sophistication and military strength today is very different from the world of 1945 [and it] is obvious that the UN and other international organisations have not evolved to keep up with the times.”⁽⁹¹⁾ If we are to restore faith in the international rule of law, I suggest that we will need to re-evaluate some of our assumptions underlying international law and re-examine some of its institutions.

48.    One such assumption is that because states are the primary subjects of international law, their internal dynamics and domestic issues can be safely written off as subsidiary concerns. The reality, however, is that at least some of the recent backlash against the rules-based order can be traced precisely to domestic undercurrents.

49.    For instance, recent changes in US trade policy arguably reveal deeper concerns about the hollowing out of American manufacturing, the perception that trade liberalisation has accelerated this decline, and the belief that the multilateral trading system works against the American working class. The 1999 anti-WTO protests in Seattle remind us that such sentiments are not entirely new. Another manifestation of this phenomenon was Brexit, which was fuelled in part by the perception that supranational decision-making bodies had become dangerously detached from the concerns of ordinary citizens and unaccountable to those most affected by their decisions.⁽⁹²⁾ These problems are not unique. The UN World Social Report 2025 warns of “a worsening crisis of institutional trust”, with 57% of respondents to the latest World Values Survey indicating that they either do not trust their government very much, or at all.⁽⁹³⁾  

50.    These examples demonstrate the very real consequences that international law and relations can have at the domestic level, and the very real need to take account of domestic realities in the design of international norms.⁽⁹⁴⁾ International law already recognises this principle in certain contexts. For instance, differences between states are accommodated through mechanisms such as treaty reservations, and through concepts such as the margin of appreciation that is afforded to states in the implementation of their human rights obligations, and the common but differentiated responsibilities that are borne by states in respect of climate change mitigation. 

51.    We should, however, also ensure that international norms are responsive to the changing needs of each state over time. One piece of this puzzle, I suggest, lies with international institutions, whose processes should support participation from a spectrum of states and civil society groups and ensure the effective representation of their interests. Another piece of the puzzle might be found in the rules for modifying legal norms. It can often be challenging to replace one customary rule with another, or to subsequently amend the provisions of large multilateral agreements.⁽⁹⁵⁾ Without flexible rules for modification, states may face a binary choice of either sticking to an outmoded rule or abandoning the treaty regime or compliance altogether. Either way, this undermines the legitimacy and effectiveness of international law.

52.    And I suggest we should also direct our attention to the health of international institutions. For some years now, we have seen states respond to institutional inadequacy by weakening or withdrawing from institutions rather than reforming them. On the other hand, and encouragingly, innovative responses to gridlock are already emerging. I will illustrate this with two examples, the first concerning the WTO Appellate Body and the second on the invasion of Ukraine. 

53.    The Appellate Body has been the subject of scrutiny for some years. Among other criticisms, it has been accused of judicial activism by interpreting obligations expansively and encroaching on the space for political negotiation.⁽⁹⁶⁾ Appointments to the body have consistently been blocked, with the term of the last sitting Appellate Body member expiring in November 2020, and it has not heard any appeals since 2019. This severely undermines the WTO Dispute Settlement Understanding, which only allows for prospective remedies after each dispute has run through the full appeals process.⁽⁹⁷⁾ Some economies have exploited this by tactically appealing adverse panel rulings “into the void”.⁽⁹⁸⁾

54.    Faced with the seemingly impossible task of reviving the Appellate Body in the foreseeable future, 19 WTO members devised a creative workaround in April 2020 by establishing a plurilateral Multi-Party Appeal Interim Arbitration Arrangement (MPIA). The MPIA maintains a two-level system of adjudication and commits its participants to arbitration as long as the Appellate Body remains unable to hear appeals for want of sufficient members.⁽⁹⁹⁾

55.    Early arbitrations under the MPIA have featured procedures that were specifically responsive to criticisms levelled against the Appellate Body – for example, that it regularly exceeded the 90-day deadline for deciding appeals,⁽¹⁰⁰⁾ and that it failed to exercise judicial restraint by reviewing the factual findings of WTO panels.⁽¹⁰¹⁾ One MPIA arbitrator has hailed the MPIA as being more than a stop-gap measure, and as a laboratory for experimental reform which sidesteps the cumbersome WTO amendment process.⁽¹⁰²⁾

56.    My second example concerns the accountability of Russia for its invasion of Ukraine. A spotlight has fallen on the International Criminal Court’s general lack of jurisdiction over the crime of aggression.⁽¹⁰³⁾ This crime has special significance, for it is a leadership crime, without which other crimes cannot take place.⁽¹⁰⁴⁾ And whereas other crimes are primarily concerned with civilians, the crime of aggression victimises both civilians and combatants alike, for it draws combatants into fighting a war that should never have been started.⁽¹⁰⁵⁾

57.    This May, the Council of Europe announced plans to fill this gap by establishing a Special Tribunal for the Crime of Aggression against Ukraine by 2026, with the mandate to prosecute senior Russian leaders.⁽¹⁰⁶⁾ Established within the Council of Europe framework but financed by a wider group of supportive states, the tribunal is intended to be both international and independent. Its proponents acknowledge that issues remain, such as the challenge of obtaining physical custody over potential defendants and the immunity enjoyed by heads of state, heads of government and foreign ministers under international law.⁽¹⁰⁷⁾ Notwithstanding this, the initiative exemplifies the spirit of adaptation and innovation that the rules-based international order desperately needs.

V. Conclusion

58.    Let me conclude by emphasising that while international law faces strong headwinds, this should not be cause for despair. International law has historically been forged in the crucible of conflict and crisis. Perhaps because of that, it has generally demonstrated a remarkable ability to transform crises into catalysts for change.⁽¹⁰⁸⁾ Indeed, the rules-based international order that rose from the ashes of the Second World War stands as a testament to this.

59.    But even more fundamentally, if there is one thing I leave with you today, it is this: we simply cannot afford to despair. From Melos to Westphalia and on to Nuremberg and the United Nations, humanity struggled through two millennia of strife and upheaval before the post-war global order was established, with its emphasis on a set of crucial values that emerged out of the collective realisation that the horrors of the Second World War should never be repeated. Those values include the prohibition on the use of force, of wars of aggression, and of genocide, and the prime importance of the sovereign equality of nations, of the right to self-determination, and of free and open trade. All these gains surely came at too heavy a price for us to lose sight of them. 

60.    And beyond the lessons from history, how could we possibly face a future that is not anchored in international law and order? I propose a thought experiment. Just imagine, if you will, a world as interconnected and interdependent as ours today, being left to confront not only the complexities of conventional geopolitical tensions, but the entire raft of pressing and structural global threats such as climate change, artificial intelligence and deepening inequality without a rules-based legal order founded on a shared commitment to international law. If that seems unthinkable, or even unimaginable, it is because it is. Indeed, this is so profoundly dystopian a picture that it does not bear thinking about. 

61.    And so, 80 years on from World War II, I suggest we have no choice. It now falls squarely on all of us to urgently defend, restore and revitalise the order we have inherited, because it needs our help and without it, humanity itself will be imperilled. Now is the time for us to honour this sacred trust; now is the time for us to act so that the law is not reduced to a mere collection of words, but rather, that it might shine as a living embodiment of our most fundamental and cherished values. Now is the time because we owe it to the generations to come.

62.    Thank you very much for your attention. I congratulate you on your 10th Anniversary. May there be many more years of productive work ahead of you in this critically important area, beginning with what I am sure will be a very fruitful symposium.