In February 2024, the International Court of Justice (ICJ) convened hearings on Israel’s activities in the Occupied Palestinian Territory. Over six days, the ICJ received oral statements from more than 50 states and international organisations – an unprecedented figure in the World Court’s nearly 80-year history at the time.Footnote 1 Five months later, the Court issued a landmark advisory opinion in which it 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.Footnote 2 Exactly two months later, the United Nations (UN) General Assembly welcomed the opinion and demanded that Israel end its unlawful presence without delay and within 12 months in any event.Footnote 3
One might fairly believe that this outcome represented 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.Footnote 4 Yet, as one law minister who participated in the proceedings observed to the Guardian newspaper, “there was an acute realisation that none of this [was] actually going to change anything on the ground”. His own, rather stark assessment of the situation 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”.Footnote 5
Those words, spoken not by a cynic but rather 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. For many, if not all, of us who are interested or invested in the project of international law, this dissonance should be deeply unsettling; and for those of us who serve as judges in particular, the belief that justice is nothing but a pipedream beyond any court’s reach must be profoundly dispiriting. Courts exist for the precise and singular purpose of dispensing justice, and the law is meant to serve the common good by affording a framework for resolving differences fairly in the real world. While ICJ advisory opinions and General Assembly resolutions are of limited legal effect by design, the seemingly indifferent disregard they have received nevertheless raises serious questions about the state of the international legal order.
Such disregard is especially concerning because the rules-based international order has, for much of modern history, served as a reliable bulwark against dramatic geopolitical upheaval since it emerged from the ashes of World War II. It has formed the bedrock for what has been a prolonged and precious 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 now stands as a defining issue of our time, which is a surprising reality given that many observers would have found this unthinkable merely a decade ago.
The central thesis of this article is that despite the prevailing gloom, the international community cannot afford to lose hope in international law and its institutions and must instead urgently renew and strengthen its commitment to the rules-based international order and to the international rule of law. This thesis will be developed by exploring four interconnected inquiries. The first part of the article outlines the conceptual and historical foundations underlying the modern rules-based international order and distils its essential characteristics. The second part juxtaposes this against the contemporary forces that threaten to undermine the rules-based international order, with a particular focus on recent developments from the past six years. The third part then articulates why we simply cannot afford to allow these forces to destroy the rules-based order, because of the profoundly critical role it plays in ensuring a fair, just, and effective system of global governance. The final part looks to the future and explores possible pathways for reimaging and revitalising international law with a spirit of sober optimism.
I. 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”.Footnote 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 in terms of the reality of its shortcomings. Familiar critiques relate to its lack of a central legislature, courts with compulsory and universal jurisdiction, or a transnational police force with ready and effective enforcement powers.Footnote 7 International law must instead typically rely on other means to secure a measure of compliance, such as the perceived value of international cooperation, the legitimacy of international institutions, and above all, a shared and abiding commitment to the international rule of law.Footnote 8
These are the very factors that underpin the rules-based international order as it exists today. Drawing inspiration from the work of Professors Monica Hakimi and Jacob Cogan, it is suggested that the rules-based international order can be understood as having at least five core features:Footnote 9
1. First, the rules-based international order engenders comprehensive legalisation, where the law represents the dominant mode of interaction between states. Across various dimensions of international relations, states assert legal norms to regulate conduct, invoke legal procedures to resolve conflicts, and conclude agreements using familiar legal structures to signal policy commitments and entrench arrangements for cooperation.
2. Second, the rules-based order embraces a statist model in which sovereign states constitute its primary actors and lawmakers. States safeguard their autonomy and authority through a suite of foundational principles, such as the principle of sovereign equality and the prohibition on aggression.
3. Third, there is a commitment to the work of international institutions. Across legal and geographic frontiers, institutions establish the highways and marketplaces for cooperation and exchange. States benefit from an intricate latticework of forums for negotiation and decision-making, vital hubs for the distribution of aid and assistance, and specialised centres of research and expertise.
4. Fourth, the rules-based order promotes the expansive regulation of human activity, both across borders and, increasingly, within the domestic sphere. Over the years, without abandoning the statist model, its field of concern has been enlarged to encompass a range of non-state actors, from foreign investors to terrorist groups.Footnote 10
5. Finally, the foundation that undergirds all of these features is the international rule of law. This encapsulates a global compact where states commit to using the law as the central means of regulating their affairs and addressing 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, based on a shared understanding that this commitment represents the only credible way of ensuring that the exercise of state autonomy does not imperil the common good.Footnote 11
These five features of the rules-based international order might seem axiomatic, especially to international lawyers. Yet, this model of international law is one that is neither self-actualising nor guaranteed. As history demonstrates, it was a hard-earned and hard-won consequence of the post–World War II settlement.
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.Footnote 12 This subordination of might to right has been hailed as one of humanity’s greatest achievements in the twentieth century and even as a manifestation of a new “civilizational consensus”.Footnote 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 UN 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.Footnote 14
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 for the trials, they 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 aggressions against the rights of their neighbors”.Footnote 15
The trials played an instrumental role in promoting the legitimacy of the new international order. They ensured that victor’s justice was administered through criminal proceedings with due process rather than summary executions.Footnote 16 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.Footnote 17
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 World War II.Footnote 18 Under this blueprint, the International Bank for Reconstruction and Development was to finance post-war 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 Organization never came into being, the General Agreement on Tariffs and Trade served to advance the agenda of trade liberalisation and significantly dampened the protectionist tendencies that had characterised the pre-war period.
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 a change of not merely degree but also kind – that international law was evolving from a law of coexistence to one of cooperation. This observation encapsulated the fundamental transformation of international law’s priorities from the securing of negative peace to the pursuit of the collective good.Footnote 19 Alongside this shift, the UN General Assembly adopted the Friendly Relations Declaration by consensus in 1970, marking the 25th anniversary of the UN. The declaration was an explicit reaffirmation that seven Charter-based principles had become cornerstones of international society.Footnote 20
II. The rules-based international order under pressure
For all its imperfections, the rules-based international order supported a remarkable period of long peace and relative prosperity. In the 2019 S. Rajaratnam Lecture, this author suggested that while the international rule of law had come under considerable strain on several occasions – sometimes, it seemed, almost to breaking point – one could still say with confidence that it remained alive and well.Footnote 21 Indeed, the first two decades of the twenty-first century were punctuated by several flashpoints that 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 international order proved remarkably (and reassuringly) resilient.
With the events of the past six years, however, there is a palpable 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.
The Covid-19 pandemic posed the first major test of the decade and, indeed, represented one of the most far-reaching and disruptive crises to confront humanity over the last century. When it was upon us, we witnessed the swift retreat of states behind the perceived safety of their borders, as many traded collective solidarity for immediate national preservation.Footnote 22 With more than seven million reported Covid-19 deaths worldwide,Footnote 23 those dark days are a poignant reminder of humanity’s shared vulnerability and our profound interdependence.
While the pandemic was a painful illustration of the international system failing to work as intended, the international community now confronts a drumbeat of dislocating developments that threaten to undermine and perhaps even dismantle the rules-based international order in far more fundamental ways. The mood of the moment was captured by Secretary-General António Guterres in an address to the UN General Assembly in 2022, when he warned that the UN Charter and its ideals are now in jeopardy, that the international community is “gridlocked in colossal global dysfunction”, and that a “winter of global discontent” is fast approaching on the horizon.Footnote 24 A concerning number of developments could illustrate this troubling trajectory, but this article will focus on two in particular: the war in Ukraine and the evolution of US foreign and trade policies.
A. The war in Ukraine
Russia’s invasion of Ukraine has been described as the most significant shock to the international order since World War II,Footnote 25 with Russia drawing widespread condemnation for its flagrant violation of the prohibition on the use of force.Footnote 26 In a ministerial statement delivered in 2022, Singapore’s Foreign Minister Dr Vivian Balakrishnan described Russia’s conduct as a “clear and gross violation of international norms” and an “existential issue” for states like Singapore.Footnote 27 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”.Footnote 28
Some scholars have suggested that what makes Russia’s conduct especially dangerous is its colourable use of the language of international law to cloak its violations with a veneer of legitimacy.Footnote 29 The ICJ has, of course, observed in Nicaragua v. United States of America 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 that rule.Footnote 30 It is suggested, however, that this can hardly be the case where the justifications proffered do not have any reasonable basis. Echoing this concern, some have commented that Russia’s apparent justifications appear to apply commonly agreed concepts in “peculiar” and even “cynical” ways, leading to a suggestion that it is using the law as a weapon of war or lawfare.Footnote 31
Professor Marc Weller, Chair of International Law and International Constitutional Studies at the University of Cambridge, has made the case that none of Russia’s justifications stand up to scrutiny:Footnote 32
1. First, there was no humanitarian emergency that might trigger the doctrine of humanitarian intervention.
2. 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.Footnote 33
3. Third, Russia was not defending the people of Ukraine, nor was Russia defending itself from Ukraine. There was no evidence of Ukraine acquiring nuclear weapons or developing biological weapons. The idea that Russia had to respond to the presence of the North Atlantic Treaty Organization (NATO) in Ukraine only serves to distort the doctrine of self-defence.
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.Footnote 34 In other words, we are dealing with a challenge of “alternative facts”, deployed to mask or divert attention from a basic violation of international law.
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 naturally a complicated and delicate exercise in diplomacy even at the best of times, but here the challenge is compounded by Russia’s veto power in the UN Security Council.Footnote 35
It should be acknowledged that criticisms surrounding the veto do not apply exclusively to Russia. Moreover, the veto system can be understood as the product of a historical compromise: the United States and the Soviet Union had made veto power a condition for joining the UN, and in this context, the veto system arguably represented an improvement over the requirement of unanimity in the League of Nations.Footnote 36 Be that as it may, the crippling effects of the veto system on conflict resolution are difficult to ignore. Between 1945 and 1992, the UN Security Council’s Permanent 5 member states exercised the veto some 279 times in relation to intervention in armed conflict – a period that saw over 100 major conflicts and some 20 million casualties.Footnote 37 The picture was particularly bleak during the Cold War, when the Security Council was effectively reduced to an arena for ideological battles between the East and the West.Footnote 38 It is perhaps unsurprising, then, that the veto system has become something of a lightning rod for criticism of the UN.
B. Evolution of US foreign and trade policies
Moving across the Atlantic, the rules-based international order has also come under strain from fundamental shifts in the foreign and trade policies of the United States. In January 2025, US 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 US]”.Footnote 39 This signalled a marked departure from the long-held position assumed by the United States as a key architect of the post-war system and, in many respects, its foremost champion and defender.Footnote 40
With these shifts, the rules-based international order faces a potential vacuum. The United States has long been the UN’s largest financial contributor, providing 22 percent of its core budget and about 27 percent of its peacekeeping budget according to 2025 figures.Footnote 41 In early 2025, however, the United States initiated a sweeping review of all multilateral organisations and treaties to which it is party.Footnote 42 This led, among other things, to its withdrawal from the 195-party Paris Agreement and the 194-member World Health Organization effective January 2026.Footnote 43 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,Footnote 44 thus potentially narrowing their scope of work. The United States has also continued to exert influence on other institutions of which it is not a member but whose actions it deems unsatisfactory – for instance, by imposing sanctions on judges and prosecutors of the International Criminal Court (ICC).Footnote 45
This turn from multilateral engagement is also apparent in US trade policy, with its increased focus on power-based bargaining backed by the threat of tariff escalation.Footnote 46 In April 2025, Singapore’s prime minister, Mr Lawrence Wong, delivered a ministerial statement in response to the US tariffs and their implications, where he observed that the new tariff regime is incompatible with the most-favoured nation (MFN) principle that underpins the World Trade Organization (WTO) system and that it opens the door to “selective country-by-country trade relationships, based on unilateral preferences”.Footnote 47 While the worst of the tariffs may not have come to pass, the dust has not settled and it may never truly settle – and that is precisely the concern. The short point is that trading relationships are now far less predictable than they once were without the assurance of certainty and stability that the WTO system was meant to provide.Footnote 48 As Prime Minister Wong reiterated at the National Day Rally in August 2025, the fact that an economy is subject to the baseline 10 percent tariff rate is of “little comfort”, because that baseline can shift and higher tariffs can still be set for specific industries.Footnote 49
Each of these developments exposes how foundational pillars of our international legal order are at risk of disintegration, if not active demolition – from bedrock principles of free trade to the existential guarantee against aggression. Collectively, what these developments suggest is a slow but perilous drift towards an international order where the international rule of law no longer constitutes its anchor but rather becomes a hollow ideal.
III. The rules-based international order as an existential necessity
The developments outlined above are a salient and urgent reminder that nothing about the present international order is assured. Even a tiny prospect that it might all come apart at the seams one day should be a prospect that gives all of us cause for pause. This is because the rules-based order represents the only hope that humanity has to develop credible and effective answers to many of its most pressing problems and needs.Footnote 50 There are at least three reasons why the rules-based order should be regarded today as an existential necessity for humanity.
First, most states depend on international law literally for their very existence. International law is plainly 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.Footnote 51 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.Footnote 52 Without the rules-based international 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 come to be accepted in the post-war era as foundational elements of the law of international relations and inalienable rights of humanity.
This reality weighs especially heavily on small states, which naturally rely on international law as both their sword and shield.Footnote 53 The iconic Melian dialogue from 416 BCE is a poignant illustration of this point. The dialogue encapsulates the invasion of the small and neutral island of Melos by Athenian forces. When the leaders of Melos appealed to justice to resist the invasion, the Athenian forces summarily dismissed their plea with a chilling declaration: “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”.Footnote 54 This alternative paradigm – of a brutal world where might makes right – would be not only arbitrary and unjust but also 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.
Second, humanity needs the rules-based international order if it is even to have a shot at tackling the gathering storm of challenges that confront us all.Footnote 55 As a brief survey readily demonstrates, the scale of these challenges is simply astonishing:
1. Greenhouse gas concentrations continue to reach record highs each year, with atmospheric carbon dioxide levels climbing to 150 percent of their pre-industrial values in 2023.Footnote 56 Some 3.3 to 3.6 billion people live in areas that are highly susceptible to the effects of climate change, and between 2030 and 2050, some 250,000 additional deaths due to climate change are expected each year.Footnote 57 Closely linked to this is the ever-looming threat of the next global pandemic. One 2025 study suggested that nearly 10 percent of the global land surface is at high or very high risk of disease outbreaks, such as Ebola and Zika.Footnote 58
2. 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,Footnote 59 and the refugee population alone has doubled since 2015 to almost 36 million.Footnote 60 This is symptomatic of the slow progress made on the UN Sustainable Development Goals (SDG) more generally. Since 2015, progress on a third of the 135 SDG targets has either stalled (18 percent) or regressed (17 percent), and the world is on track to achieve only 17 percent of the targets by 2030.Footnote 61
3. Rapid advancements in artificial intelligence (AI) systems have also introduced a host of new challenges for areas such as human accountability, cybersecurity, and grey zone warfare, and this has prompted the UN General Assembly to adopt some of its first resolutions on AI in 2024.Footnote 62
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.Footnote 63 At their core, many of these challenges are concerned with the coordination of global public goods that cannot be fully controlled, produced, or regulated by any single state, and the management of negative externalities that arise from the unchecked exercise of state autonomy.Footnote 64
What these transnational challenges in turn underscore is the need for robust international institutions. As Professor Harold Koh observed, the very function of international organisations is to “organize proactive assaults on all manner of global problems” and to elevate systemic concerns over parochial interests.Footnote 65 One of the greatest strengths that international organisations possess is precisely their convening power and their remarkable ability to keep critical issues on the global agenda for decades.Footnote 66 Another key strength is their capacity to recalibrate the dynamics of international cooperation and confer real agency upon small states that might otherwise be sidelined or overlooked in an increasingly crowded international playing field.
A third justification for the importance of the rules-based international order is that in many cases, international institutions alone can realistically offer solutions that display staying power and command greater legitimacy than purely national responses. This is especially true in the space of third-party dispute resolution.Footnote 67 To build on an earlier example, while it is no doubt possible for the Ukrainian courts to prosecute perpetrators in relation to the Russian invasion (as they have done), such prosecutions can easily become entangled in a web of complex issues concerning capacity, expertise, and quite inevitably, perceived independence.Footnote 68 As one author observed, it is inherently difficult for such proceedings to “escape the taint of victor’s justice or, as the case may be, victim’s revenge”.Footnote 69
IV. Revitalising the rules-based international order
In this light, the rules-based international order faces a stark paradox. It is now more indispensable than ever, yet it is also more endangered than ever. Standing precariously at this crossroad, it is critical that the international community grapples constructively with fundamental questions about our collective future and the way ahead.
The views of international lawyers on the future of international law are as varied as they are revealing. An article in the Guardian memorably observed that “[i]nternational lawyers are themselves divided over whether their discipline is alive and well, in hibernation, in its death throes, or long ago deceased, a ‘moral ghost’ that hovers over the world map”.Footnote 70 Sir Daniel Bethlehem, for example, has described the post-war institutions as “sclero[tic]” and unfit for purpose, and has prescribed a course of radical reimagination.Footnote 71 On the other hand, the diagnosis offered by ICJ Judge Dire Tladi is that the world faces a failure of not international law but rather international politics.Footnote 72 Whichever view one adopts, the international order is in serious need of urgent help.
The starting premise must be that the international community cannot afford to jettison the rules-based international order. There is much that humanity has achieved with the present system that should be jealously guarded, such as the widely (and, until recently, one might say universally) accepted prohibition on the use of force.Footnote 73 At the same time, it may be unduly sanguine to regard recent developments as nothing but a mere aberration that will leave the international order fundamentally unscathed.
What the international community arguably needs is a spirit of sober optimism – one that recognises the immense and timeless value of the wider project of international law, but without subscribing dogmatically to all of its ideas. Translating this spirit into action demands two key imperatives: we must vigorously defend the international rule of law with greater clarity and conviction, while being prepared to honestly confront the weaknesses that have eroded faith in the rules-based international order, even if this means abandoning that which is familiar or customary. Each of these imperatives warrants closer examination.
A. Affirming the international rule of law
First, it is crucial that states fiercely defend the primacy of the international rule of law and present a united stand in calling out and condemning violations of its cardinal norms. It is precisely when faith in the rules-based international order is backsliding in some quarters that it requires our most resolute and concerted defence.Footnote 74
This commitment is essential not because it will 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 Judge 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”.Footnote 75 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.Footnote 76
We should thus be encouraged that a sizeable majority of states have publicly registered and reiterated their concern over the developments in Ukraine and the Occupied Palestinian Territory, and that many have demonstrated their readiness to mobilise substantial resources in defence of 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 to be held since 1950.Footnote 77 This was matched by a host of tangible measures that ranged from military assistance to criminal prosecution.Footnote 78 As noted in the introduction, the General Assembly also adopted two resolutions that sought advisory opinions from the ICJ on Israel’s obligations under international law in relation to the Occupied Palestinian Territory.Footnote 79
Another noteworthy development was the launch of the Global Initiative to Galvanize Political Commitment to International Humanitarian Law. This initiative was launched by the International Committee of the Red Cross and a geographically diverse group of states, including Brazil, China, France, Jordan, Kazakhstan, and South Africa. What the initiative seeks to achieve is not a new convention but rather actionable recommendations that ensure that international humanitarian law commands the political attention it deserves when conflicts erupt. It also seeks to foster dialogue on persistent challenges such as the prevention of violations. The initiative is expected to culminate in a landmark High-Level Meeting to Uphold Humanity in War in 2026.Footnote 80
While denouncing violations of international law when they arise is of signal importance, it should not be the case that international law assumes salience only when breaches occur. Instead, states should positively expand and intensify their engagement with international institutions and processes at every level and on every plane. This need is especially pressing in relation to institutions like the UN, which is in many ways the sole institution capable of bringing all states together within the same forum and fostering truly universal multilateralism.Footnote 81 The value of deepened engagement has been clearly demonstrated by the growing momentum achieved in the area of climate justice. In 2024 and 2025 alone, the European Court of Human Rights,Footnote 82 the International Tribunal for the Law of the Sea,Footnote 83 and the Inter-American Court of Human RightsFootnote 84 have all issued major rulings that not only recognise but also emphatically underscore the obligations of states to mitigate and respond to climate change. And in July 2025, the ICJ ruled in a rare unanimous opinion that climate inaction can fully engage the responsibility of states by triggering a constellation of obligations under international law.Footnote 85 Remarkably, the ICJ proceedings drew widespread participation from nearly a hundred states and a dozen international organisations. The genesis of the case is no less striking: what initially began as a university project by a group of students from Vanuatu to explore pathways for climate action eventually crystallised in the UN resolution that requested the Court’s opinion, which itself commanded the support of more than 130 states.Footnote 86
This last point highlights how international lawyers and civil society, too, bear an equally weighty responsibility in the 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 their sustained advocacy, they have shaped the very discourse through which international norms evolve and to which states are held to account.Footnote 87
To take two examples close to home, this proud tradition of consensus-building and principled engagement has underpinned the work of two of Singapore’s distinguished lawyer-diplomats: Ambassadors Tommy Koh and Rena Lee. Among their many contributions, both ambassadors played a pivotal role in securing the conclusion of two groundbreaking treaties that concern our global commons. Indeed, their contributions have been so significant that Ambassador Koh has been referred to as the “midwife” of the United Nations Convention on the Law of the Sea, and Ambassador Lee as the “mother” of the Agreement on Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ).Footnote 88
This tradition also sustains the work of international non-governmental organisations such as the International Law Association (ILA) in strengthening respect for international law. Founded in 1873, the ILA boasts a membership of some 5,500 members from 67 branches around the world, who study issues ranging from global health law to AI and technology law under the umbrella of 20 active committees. Notably, a new study group was established in May 2025 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”.Footnote 89
B. Acknowledging and addressing the weaknesses of the international legal order
A genuine commitment to the rules-based international order does not, however, entail an unquestioning acceptance of all of its features, no matter how flawed or outmoded these features may be. Adopting an uncritical approach would only operate to erode the legitimacy of the international order further.
As Singapore’s foreign minister observed when he delivered the country’s national statement to the UN General Assembly in September 2025, “[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”.Footnote 90 If we are to take seriously the goal of restoring faith in the international rule of law, we will need to re-evaluate some of the assumptions underlying our frameworks of international law and re-examine some of its institutions.
One such assumption is that because states constitute the primary subjects and basic units of international law, their internal dynamics and domestic issues can be safely written off as subsidiary concerns. Such a view, however, ignores the reality that at least some of the recent backlash against the rules-based international order can be traced precisely to domestic undercurrents.
For instance, recent shifts in US trade policy arguably reflect 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. Brexit represents another manifestation of this phenomenon. It 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.Footnote 91 These problems are not at all unique. As the UN World Social Report 2025 warns, the world faces “a worsening crisis of institutional trust”, with 57 percent of respondents to the latest World Values Survey indicating that they either do not trust their government very much or at all.Footnote 92
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 domestic realities into account in the design of international norms.Footnote 93 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.
We should, however, also ensure that international norms remain responsive to the changing needs of each state over time. One piece of this puzzle conceivably lies with international institutions, who should ensure that their processes support the ongoing participation of a spectrum of states and civil society groups, and 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 by amassing the requisite state practice and opinio juris, or to formally amend the provisions of large multilateral agreements.Footnote 94 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 can serve to undermine the legitimacy and effectiveness of international law.
In addition to the evolutionary capacity of international norms, our attention should also be directed to the sustained health of international institutions. For some years now, we have seen states respond to institutional inadequacy by weakening or withdrawing from institutions instead of choosing the path of reform. Such an approach is ultimately self-defeating, however, for it leaves the international community with fewer tools to address shared challenges.
Against this backdrop of institutional retreat, there are encouraging signs that innovative responses to institutional gridlock are already emerging. Two examples involving the WTO Appellate Body and the ICC illustrate this trend.
The WTO Appellate Body has been the subject of scrutiny for some time. Among other criticisms, it has been accused of judicial activism by interpreting obligations expansively and encroaching on the space for political negotiation.Footnote 95 It has not heard any appeals since 2019, as appointments to the body have consistently been blocked, such that the term of the last sitting Appellate Body member expired in November 2020. This state of paralysis severely undermines the WTO Dispute Settlement Understanding, which is designed to allow for prospective remedies only after each dispute has run through the full appeals process.Footnote 96 Some economies have exploited this by tactically appealing adverse panel rulings “into the void”.Footnote 97
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.Footnote 98 Early arbitrations conducted under the MPIA have featured procedures that were specifically responsive to criticisms levelled against the Appellate Body – such as criticisms that it regularly exceeded the 90-day deadline for deciding appealsFootnote 99 and that it failed to exercise judicial restraint by overstepping its role and reviewing the factual findings of WTO panels.Footnote 100 One MPIA arbitrator has described the arrangement as more than a mere stop-gap measure and hailed it as a laboratory for experimental reform that helpfully overcomes the cumbersome WTO amendment process.Footnote 101
A further example of institutional innovation can be found in the attempts to hold Russian leaders to account for the invasion of Ukraine. A spotlight has fallen on the ICC’s general lack of jurisdiction over the crime of aggression.Footnote 102 This is a crime of special significance, for it is a leadership crime without which other internationally recognised crimes cannot take place.Footnote 103 Moreover, whereas other crimes are primarily concerned with the infliction of harm on 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.Footnote 104
In May 2025, 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.Footnote 105 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 various 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.Footnote 106 Notwithstanding this, the initiative exemplifies the spirit of adaptation and innovation that the rules-based international order desperately needs.
V. Conclusion
While it can hardly be denied that 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, and perhaps because of that, it has consistently demonstrated a remarkable ability to transform crises into catalysts for change.Footnote 107 Indeed, the rules-based international order that rose from the ashes of World War II stands as a towering testament to this.
Even more fundamentally, however, humanity simply cannot afford to despair. From Melos to Westphalia and on to Nuremberg and the UN, 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 World War II should never be repeated. Those values include the prohibition on the use of force, wars of aggression, and genocide, and the prime importance of the sovereign equality of nations, the right to self-determination, and free and open trade. All these gains surely came at too heavy a price for us to lose sight of them.
Beyond the lessons from history, how could we possibly face a future that is not anchored in international law and order? As a thought experiment, just imagine a world as interconnected and interdependent as ours today, being left to confront not only the complexities of conventional geopolitical tensions but also the entire raft of pressing and structural global threats such as climate change, AI, and deepening inequality without a rules-based legal order founded on a shared commitment to the international rule of 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.
Eight decades on from World War II, it 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 and to act so that the law is not reduced to a mere collection of words but instead shines as a living embodiment of our most fundamental and cherished values. Now is the time because we owe it to the generations to come.
Acknowledgements
The author is deeply grateful to his colleagues, Assistant Registrars Bryan Ching and Ong Kye Jing, for all their assistance in the research for and preparation of this article.
Funding statement
None.
Competing interests
The author declares none.
Sundaresh MENON is the Chief Justice of the Supreme Court of Singapore.
