Why Russia’s Aggression Against Ukraine Cannot Be Cured by a Vote : A Legal and Historical Reality Check

Why Russia’s Aggression Against Ukraine Cannot Be Cured by a Vote  

A Legal and Historical Reality Check

By Greta Ramelli, Kateryna Kyrychenko, David Griffiths, Clyde Freeman, Anastasia Zaluckyj, Dmytro Panchenko and Rahul Ramesh

Introduction

A persistent assumption in some policy debates is that concessions of territories under Russia’s occupation will offer a pathway to ending Russia’s war against Ukraine. The Trump administration has repeatedly supported this thesis. While European officials have generally been more cautious, the possibility of territorial compromise has nevertheless entered public debate, including in Ukraine. Ukrainian officials have, however, distinguished between acknowledging the difficulty of restoring control by force in the near term and legally recognizing Russia’s claims over occupied territory.

Yet, this argument rests on a critical assumption that ceding territories would be sufficient to stop Russia’s aggression. This premise is far from settled. Analysts have repeatedly noted that Russia’s war aims extend well beyond Donbas, Crimea, or the mere acquisition of territory. The conduct of the war, characterized by war crimes and crimes against humanity, including systematic attacks on civilian infrastructure, forced deportations, and efforts to erase Ukrainian cultural identity, raises serious doubts about whether any concession, large or small, would meaningfully alter Russia’s strategic objectives. The trajectory of the war suggests the opposite: that Russia’s war is more than just an attempt to gain strategic territories and that ceding some territories is unlikely to bring peace.

Even if it is doubtful that territorial concessions would meaningfully alter the course of Russia’s campaign, it is still necessary to examine all potential scenarios that could influence how the war might eventually conclude. Considering these possibilities does not suggest that concessions are advisable or likely to succeed; it just reflects the need to understand the full range of legal, historical, and practical constraints that would shape any hypothetical settlement. 

Assuming (purely for the sake of analysis) that territorial concessions could form part of a hypothetical negotiation, far more difficult questions immediately arise: how would such concessions be made? What legal mechanisms would be required? What constraints would international law impose? What limits does Ukrainian constitutional law create? And what can be learned from past conflicts in which referenda, territorial claims, or post‑conflict votes were used or proposed?

These questions are not abstract. They go to the heart of whether territorial concessions are legally possible and historically realistic, even before one considers whether they are politically desirable. This blog post therefore examines the legal architecture, domestic constitutional constraints, and historical precedents that shape what is and is not possible.

International Law Framework

The international legal order that emerged after 1945 is built on two core principles: the prohibition of the use of force and the prohibition of territorial acquisition through aggression. These rules are reinforced by the duty of non‑recognition, which obliges states not to accept territorial changes produced by unlawful force. This framework raises a foundational question: whether international law allows to legitimize a territorial change that originated in the use of force against a sovereign country and consequential occupation.  

The historical development of modern international law strongly suggests that it does not.  The modern international legal framework begins with the opposite presumption: under the United Nations system, territorial change achieved through force is presumptively unlawful.  When the breach is sufficiently serious, other member states incur derivative obligations to not recognize the resulting situation as lawful and not to assist in maintaining it - principle of non recognition. That architecture exists for a reason. If an aggressor could seize territory first and then normalize the seizure through a vote conducted in the shadow of military coercion, the prohibition on acquisition by force would be emptied of its practical content.

For much of the eighteenth and nineteenth centuries, the law of nations did not truly prohibit conquest.  On the contrary, conquest was widely treated as a recognized mode by which sovereignty over territory could pass from the defeated state to the victor, often formalized through peace settlement, acquiescence, or effective control.

WWI supplied the first decisive building blocks of that transformation. In the Pact of Paris of 1928, the major powers and many other states renounced war “as an instrument of national policy,” undermining the premise that war could remain an ordinary juridical mechanism for revising borders. The Stimson Doctrine, articulated after Japan’s actions in Manchuria, pushed the legal consequences of that shift further:  the United States announced that it would not recognize territorial or treaty changes brought about by means contrary to the Pact of Paris. That move was noteworthy not merely as a diplomatic tool, but as a legal method.  It translated the emerging anti-war norm into a rule of non-recognition, severing the traditional link between military success and legal title.  In policy terms, the point was straightforward: if aggressors could keep the fruits of unlawful force, the nominal renunciation of war would be largely symbolic.  Non-recognition was designed to prevent precisely that result.

The United Nations Charter turned the WWI shift into the foundational bedrock of the post-1945 legal order.  Article 2(4) of the United Nations Charter prohibits any threat or use of force by one state against another that affects territorial integrity, political independence, or is otherwise inconsistent with the purposes of the UN.  The International Court of Justice has explained that the two notions of threat or use of force stand together:  if the contemplated use of force would be unlawful, the threat of using that force is also unlawful.  International law and state practice overwhelmingly interpret “force” in Article 2(4) to mean armed force and subsequent international law instruments made increasingly clear that this prohibition was not simply about regulating hostilities but about denying legal rewards for coercive territorial revision.

The UN Security Council Resolution 242, adopted after the 1967 war, famously emphasized the “inadmissibility of the acquisition of territory by war.”  The Friendly Relations Declaration of 1970 went further, stating that the territory of a state shall not be the object of acquisition resulting from the threat or use of force and that no territorial acquisition resulting from such force shall be recognized as legal.  The 1974 Definition of Aggression gives concrete illustrations of the conduct at issue, identifying invasion, attack, military occupation, annexation by force, bombardment, blockades, and attacks on another state’s armed forces as exemplary cases.  It further treats aggression as the most serious form of illegal force and provides that no territorial acquisition resulting from aggression shall be recognized as lawful.  And the Helsinki Final Act of 1975 regionally consolidated the same principle by coupling territorial integrity and inviolability of frontiers with an express commitment that no occupation or acquisition produced by force would be recognized as legal. Together, these instruments reflect a legal system learning from earlier geopolitical catastrophes: peace and self-determination cannot survive if armed coercion remains a lawful pathway to sovereignty. Subsequent practice confirmed these principles (Jerusalem, Golan Heights, Namibia.) 

Article 41 of the International Law Commission’s Articles on State Responsibility later codified the same point in general form: no state shall recognize as lawful a situation created by a serious breach, nor render aid or assistance in maintaining it.  The subtending policy logic is again unmistakable.  A prohibition on conquest would be too easily circumvented if third-party states remained free to normalize, finance, or otherwise stabilize the territorial outcome of unlawful force. Post-Cold War practice reinforced rather than weakened these principles. When Iraq attempted to annex Kuwait in 1990, the Security Council responded in no uncertain terms:  annexation under any pretext had no legal validity and was null and void, and all states were called upon to not recognize it.  The International Court of Justice’s (ICJ) 2004 Wall Advisory Opinion further linked the prohibition on territorial acquisition by force to the right of self-determination and to the obligations of third-party states.  As summarized by the ICJ, the construction of the wall and its associated regime constituted de facto annexation, and all states were under an obligation not to recognize the illegal situation and to not render aid or assistance in maintaining it.  

The international community’s response to Russia’s aggression against Ukraine is consistent with international law and state practice.  In 2014, the UN General Assembly affirmed Ukraine’s sovereignty and territorial integrity, noted that the Crimea referendum had not been authorized by Ukraine, and stated that it could not form the basis for altering Crimea’s status; states were called upon not to recognize any status change based on that referendum.  In the context of Russia’s full-scale aggression against Ukraine in 2022, Russia organized what the UN General Assembly called “illegal so-called referendums” in occupied parts of Donetsk, Luhansk, Kherson and Zaporizhzhia oblasts.  The UN General Assembly held that those actions had no validity under international law and could not form the basis for altering the status of those regions, again calling on all states not to recognize any purported change. 

In this sense, the problem is not only Ukraine’s sovereignty but the integrity of the global system itself. Any concession made while Russian forces occupy Ukrainian territory would therefore sit uneasily, if not incompatibly, with the core principles that underpin contemporary international law.

Domestic Law Framework

The second issue concerns Ukraine’s own domestic legal framework, which imposes independent and exceptionally stringent constraints on any attempt to alter the country’s territory. Ukrainian law contains a set of provisions that together form a territorial‑integrity safeguarding system. Ukraine’s Constitution defines the territory of Ukraine as indivisible and inviolable, assigns the protection of territorial integrity as a fundamental duty of the state, and requires that any change to Ukraine’s territory be approved by an all‑Ukrainian referendum. 

These provisions are reinforced by two further constitutional limits that are decisive in the present context: 

1. amendments to the Constitution may not be adopted during periods of martial law, and

2. no amendment may be oriented toward the violation of Ukraine’s territorial indivisibility. 

Taken together, these rules mean that territorial concessions would in practice require a constitutional amendment, however the Constitution prohibits amendments during martial law. The first legal precondition for any territorial concession would therefore be the termination of martial law. Only once martial law is lifted could a constitutional amendment even be proposed, let alone submitted to the electorate under Article 73 of the Constitution. This structure raises a further question: even if martial law were lifted, could a referendum lawfully authorize the constitutional amendment needed to permit territorial concessions? 

Holding A Referendum to Permit Territorial Concessions

The Constitution frames referenda as an instrument of popular sovereignty and one of the principal forms of direct democracy through which the people express their will. All citizens aged eighteen or older, except those deemed legally incompetent by a court, have the right to participate. The Constitution provides several pathways for triggering an all‑Ukrainian referendum. In the territorial context, Article 73 of the Constitution gives Ukrainian Parliament the authority to designate such a referendum. For amendments to Chapters I, III, and XIII of the Constitution, its Article 156 requires that the draft amendment be introduced by the President or by at least two‑thirds of the Parliament, adopted by a two‑thirds vote, and then approved by an all‑Ukrainian referendum designated by the President. A popular‑initiative referendum is also possible in principle, but under the 2021 Law of Ukraine “On all-Ukrainian referendum” it is limited to questions of nationwide significance and repeal of laws, and cannot be used for territorial‑change questions.

These mechanisms underscore that a referendum is not a free‑floating plebiscite. It is embedded in a constitutional sequence that presupposes the existence of a constitutionally permissible draft amendment. This is where Article 157 becomes central. Read together with the Constitution’s Article 2, which declares Ukraine’s territory indivisible and inviolable, and Article 9, which provides that treaties inconsistent with the Constitution may be concluded only after relevant constitutional amendments, Article 157 creates a substantial constitutional constraint on any theory that a referendum could be used to validate territorial concessions. 

The referendum mechanism in Article 156 does not displace these limits; it operates only at the end of the amendment process and only if a draft amendment has already passed constitutional review. In practice, Article 157 creates both a substantive obstacle, as any amendment enabling territorial concessions may be deemed oriented toward violating Ukraine’s territorial indivisibility, as well as a temporal obstacle, because the amendment route is categorically closed while martial law remains in force. For present purposes, Article 157 is therefore not merely a background amendment rule. It is one of the central constitutional limits on using referendum‑based mechanisms to pursue a war‑ending territorial settlement.

The statutory framework reinforces these constitutional limits. The 2021 Law “On all‑Ukrainian referendum” defines the permissible subject matter of referenda and expressly prohibits questions that contradict the Constitution, violate sovereignty or territorial integrity, threaten national security, or contravene generally recognized principles of international law. For territorial‑change referenda, the Law adopts a treaty‑ratification model: a referendum does not ask voters whether territory should be ceded; it asks whether they approve a law ratifying an international treaty that changes Ukraine’s territory. The sequence is clear: a treaty is negotiated, the Parliament adopts a ratification law, and the referendum approves or rejects that ratification law. This design ties the referendum to the ordinary constitutional roles of the political branches and prevents the use of referenda as an alternative constitutional pathway.

The Role of the Constitutional Court of Ukraine

Throughout this process, the Constitutional Court of Ukraine acts as a mandatory constitutional gatekeeper through mandatory review in key stages of the process. It reviews the constitutionality of referendum questions and the acts calling a referendum, as well as the constitutionality of treaties altering Ukraine’s territory. It must also issue a preliminary opinion confirming that any draft constitutional amendment complies with Articles 157–158 of the Constitution before the Parliament may consider it. Opening constitutional proceedings automatically suspends the referendum process, and the Constitutional Court’s decisions are final and unappealable. This means that no referendum, no treaty, and no amendment can proceed if the Constitutional Court finds it unconstitutional, which acts as a critical safeguard in the context of territorial integrity.

Taken as a whole, Ukraine’s constitutional and statutory framework establishes a comprehensive legal architecture that leaves virtually little, if no room for territorial concessions. Because constitutional amendments are both substantively restricted and temporarily barred during martial law, no amendment enabling territorial change can even be initiated until martial law is lifted. 

And even once that threshold is met, any proposed amendment would still have to survive the Constitution’s substantive limits on altering territorial indivisibility, pass through the heightened amendment procedure, and be submitted to a nationwide referendum. That referendum, in turn, cannot operate as a workaround: it comes only at the end of a constitutionally valid amendment process, and the 2021 Law of Ukraine “On all-Ukrainian referendum” prohibits questions that undermine sovereignty or territorial integrity. 

Throughout this entire sequence, the Constitutional Court exercises mandatory and suspensive review, with the authority to halt or invalidate any step that conflicts with constitutional principles. In effect, Ukrainian domestic law does not merely make territorial concessions difficult. It constructs a layered system of constitutional and statutory safeguards that, under current conditions, renders such concessions legally unattainable under current constitutional conditions.

The Historical and Comparative Practice

The third issue concerns historical practice. Historical experience offers a clear answer to the question of whether territory seized through aggression can be legitimized through a referendum or similar process. Across a century of state practice, no credible precedent exists in which a territorial change produced by force was later validated through a vote conducted under occupation or coercive conditions. Instead, the record shows that legitimate referenda on territorial status have occurred only after the end of hostilities, the withdrawal of foreign forces, and the establishment of conditions that allow the population to express its will freely. 

The Saarland 

The Saarland plebiscite of 1935 illustrates this pattern. Although the region had been contested between France and Germany, the referendum took place only after fifteen years of League of Nations administration, the demilitarization of the territory, and the creation of a detailed legal and administrative framework overseen by international actors. Voter registration, dispute resolution, and security were all managed by neutral authorities, and both France and Germany formally pledged to abstain from pressure. The vote was accepted not because it ratified a territorial acquisition by force, but because it occurred in a demilitarized environment under international supervision. The Saarland example demonstrates that international administration and the absence of coercion are essential preconditions for a credible territorial referendum.

East Timor 

East Timor’s 1999 independence referendum reinforces this lesson. After decades of violent Indonesian occupation, the United Nations organized and administered a vote on self‑determination. The referendum was held only after Indonesia agreed to allow it, and even then, the aftermath saw severe violence that required a multinational peacekeeping force and a UN transitional administration. The referendum’s legitimacy rested on the fact that it was not an attempt to validate Indonesia’s prior annexation, but rather a mechanism — facilitated by the UN — to end an unlawful occupation and restore self‑determination. East Timor shows that international involvement is indispensable when a population has been subjected to coercion or occupation, and that referenda cannot legitimize territorial changes produced by force.

Scotland and Catalonia 

The experiences of Scotland and Catalonia highlight the centrality of constitutional legality. Scotland’s 2014 independence referendum proceeded only because the UK and Scottish governments negotiated a lawful pathway through a Section 30 Order. When Scotland later attempted to legislate a second referendum without Westminster’s consent, the UK Supreme Court held the measure unlawful. Catalonia’s 2017 referendum, conducted in defiance of the Spanish Constitution and in the face of active state opposition, was met with police intervention, judicial invalidation, and the suspension of Catalonia’s autonomy. These cases show that even peaceful, democratic referenda lack legal effect when conducted outside constitutional procedures, and that constitutional order is a prerequisite for any credible expression of self‑determination.

Kosovo

Kosovo represents an exceptional case shaped by mass atrocities, NATO intervention, UN administration, and the collapse of domestic governance structures. The International Court of Justice’s advisory opinion did not validate territorial acquisition by force; rather, it held that Kosovo’s declaration of independence did not violate international law because it did not purport to alter another state’s territory through aggression. Kosovo underscores that international law may accommodate alternative pathways only when ordinary constitutional processes are impossible due to severe human rights violations and the breakdown of state authority — conditions fundamentally different from attempts to legitimize territorial conquest.

Taken together, these precedents point to a consistent conclusion. Territory taken through aggression cannot be legitimized through a referendum or any other process conducted under coercion, occupation, or constitutional illegality. Legitimate territorial referenda require the withdrawal of occupying forces, the restoration of security, the reestablishment of constitutional order, and, in many cases, international supervision. Where these conditions are absent, the international community has uniformly rejected attempts to validate territorial change. Historical practice therefore reinforces what international law already makes clear: aggression cannot be cured by a vote.

Conclusion: Russia’s Unlawful Territorial Acquisition Cannot Be Cured

Under international law, Ukrainian domestic law and historical practice, the answer to whether aggression-based territorial change can be legitimized through a referendum is negative. 

Under Ukraine’s constitutional framework, there is no lawful pathway to a referendum that could ratify a territorial concession. Any such treaty would immediately collide with the Constitution’s guarantees of territorial indivisibility, and Article 157 of Ukraine’s Constitution bars amendments that would undermine that principle while also prohibiting all constitutional amendments during martial law. Because the referendum mechanism operates only at the end of a valid amendment process, it cannot bypass these limits. As long as martial law remains in force, and as long as territorial integrity remains a constitutional constant, a nationwide vote cannot be used to legitimize the loss of Ukrainian territory.

International law reaches the same conclusion. Since 1945, the prohibition on aggression has been paired with the principles of territorial integrity, non‑recognition, and non‑assistance precisely to prevent an aggressor from converting military control into lawful title through later political formalities. The right of self‑determination does not authorize territorial transfers engineered under foreign occupation or coercion; it protects the free political will of a people, not outcomes produced in the shadow of force. Even if a referendum were somehow held after an unlawful seizure of territory, it would not retroactively validate the original breach or relieve other states of their obligation to withhold recognition from territorial changes procured by aggression.

Historical practice reinforces this legal structure. Credible referenda on territorial status have occurred only after the withdrawal of occupying forces, the restoration of security, and the creation of conditions that allow voters to participate freely. The Saarland, East Timor, and other internationally supervised processes demonstrate that legitimacy requires demilitarization, neutrality, and constitutional or treaty‑based authorization. Where these conditions were absent (as in Catalonia or in referenda conducted under occupation) the results were rejected. No historical precedent supports the idea that territory seized through aggression can later be legitimized by a vote. 

Considered together, domestic constitutional constraints, international legal norms, and historical precedents all point in the same direction: legitimizing territorial concessions made under aggression lacks legal foundation and practical justification. And in any case, there remains scant evidence that such concessions would bring Russia’s campaign to an end.

PILPG Roundtable Blog Part II: Ukraine’s (Extraordinary) EU Accession: Security, Politics, and Strategic Necessity

PILPG Roundtable Blog 

Part II: Ukraine’s (Extraordinary) EU Accession: Security, Politics, and Strategic Necessity

Editor’s Note

Ukraine’s accession to the European Union has increasingly moved beyond the realm of technical enlargement policy and into the center of Europe’s geopolitical and security debate. As Russia’s war against Ukraine continues to reshape the European security order, questions surrounding enlargement are no longer confined to procedural benchmarks or institutional sequencing. They now concern deterrence, strategic credibility, and the future direction of the European project itself.

On 8 May 2026, members of PILPG’s Ukraine Peace Negotiations Working Group convened for a second roundtable discussion examining whether the current geopolitical moment requires the European Union to rethink how accession itself is approached during wartime. Building on an earlier discussion focused on enlargement as a strategic imperative, participants explored the political feasibility of “extraordinary accession,” the domestic constraints facing member states, the relationship between EU membership and European security, and the broader institutional implications of Ukraine’s candidacy for the European Union.

Across the discussion, one theme consistently emerged: Ukraine’s accession is no longer viewed solely as a future enlargement question. It has become a test of whether the European Union can adapt its political and institutional tools to a radically altered security environment.  

1. Extraordinary Times and Extraordinary Accession

Dr. David Crane, Founding Chief Prosecutor of the UN Special Court for Sierra Leone and Founder of the Global Accountability Project

Russia’s full-scale aggression against Ukraine fundamentally changes the logic of enlargement. In ordinary circumstances, a lengthy procedural accession process may appear entirely reasonable. But aggression on this scale, occurring in the heart of Europe, creates circumstances that many participants viewed as exceptional. From this perspective, accession becomes more than a technocratic exercise, it rather becomes a strategic political signal. A prolonged 12–14 year process risks reinforcing precisely the kind of strategic ambiguity the Russian state has historically exploited. Time and distraction remain among Vladimir Putin’s greatest strategic advantages.

Extraordinary accession, therefore, is not necessarily about bypassing reforms or eliminating conditions altogether. Rather, it reflects the argument that wartime enlargement may require different sequencing, where political commitment and strategic anchoring precede full technical completion rather than follow it years later.

Prof. Milena Sterio, the Joseph C. Hostetler-BakerHostetler Professor of Law at Cleveland State University College of Law and Managing Director at the Public International Law and Policy Group 

Ukraine’s case differs fundamentally from previous enlargement rounds because the war itself is directly connected to Ukraine’s European aspirations. This is not simply a country that happens to be at war while seeking accession. The conflict itself emerged, in part, from Ukraine’s sovereign decision to pursue a European future. That distinction transforms accession into something larger than enlargement policy alone. Political integration into Europe increasingly becomes part of Europe’s response to attempts to violently reverse a sovereign democratic choice.

Ambassador Jorge Lomonaco, former Ambassador of Mexico to the UN Human Rights Council, and to the Organization of American States 

At the same time, translating this strategic logic into EU policy remains politically difficult. Brussels is institutionally designed around procedure, consensus-building, and gradual sequencing. The European Union has historically struggled to operate outside established frameworks, even during periods of geopolitical disruption.

An accelerated or politically exceptional accession model would therefore require the EU to think in ways that are largely unfamiliar to its institutional culture. It would also further shift responsibility for European security toward Europe itself, reinforcing that Ukraine’s future is increasingly a European strategic question.

Kateryna Kyrychenko, Head of Ukraine Legal Affairs and Program Management at the Public International Law and Policy Group

For Ukraine, accession cannot be separated from the origins of the war itself. The 2014 Revolution of Dignity and the Association Agreement process reflected a broader societal choice in favor of sovereignty, democracy, and European integration. These aspirations became one of the core triggers of Russian aggression. From the Ukrainian perspective, leaving the country in a prolonged geopolitical “grey zone” does not preserve stability. It risks perpetuating the vulnerability that Russia has consistently sought to exploit.

2. The Real Obstacles: EU Domestic Politics and Enlargement Fatigue

Dr. Paul R. Williams, Rebecca I. Grazier Professor of Law and International Relations at American University and Co-Founder of the Public International Law & Policy Group

A major challenge is no longer simply whether European leaders support Ukraine’s eventual accession, but how that accession is framed politically within member states themselves. While many governments publicly support Ukraine’s European future, domestic political realities increasingly shape how far and how quickly those commitments can translate into policy.

A widening gap remains between the geopolitical arguments surrounding Ukraine’s accession and the procedural language through which enlargement continues to be discussed in Brussels. Concerns surrounding fiscal redistribution, institutional balance, and domestic political backlash remain politically salient across many European countries. Support for Ukraine’s accession is therefore often expressed through the language of sequencing, criteria, and technical readiness rather than strategic necessity. If accession continues to be framed primarily as a technical enlargement exercise, domestic political caution is likely to dominate the conversation. Framing accession instead as part of Europe’s long-term security and strategic stability may prove more politically persuasive across member states.

Emma Bakkum, Counsel at the Public International Law and Policy Group

Support for Ukraine and support for accelerated accession are not always politically identical positions within European capitals. In countries such as the Netherlands, support for Ukraine remains strong, including support for eventual EU membership. Yet this support often remains tied to the expectation that accession proceeds according to established procedures and institutional rules.

Fiscal redistribution, voting balances inside EU institutions, and the implications of integrating a large wartime economy continue to shape domestic political debate. These concerns are often less about opposition to Ukraine itself than uncertainty about how enlargement would reshape the Union internally. Governments may support Ukraine strategically while still needing to justify accession politically to electorates increasingly shaped by Euroscepticism, economic caution, and political fragmentation.

Greta Ramelli, Legal Officer, Program Manager at the Public International Law & Policy Group

Enlargement fatigue continues to influence public opinion across Europe. Earlier rounds of expansion, and the political tensions that followed them, continue to shape perceptions of future enlargement today. In this context, skepticism toward Ukraine’s accession is often tied not only to Ukraine itself, but also to broader concerns about institutional cohesion, democratic backsliding, and the long-term direction of the European Union after previous enlargement rounds.

At the same time, public conversations surrounding security and defense have shifted significantly in Europe. As the European security environment evolves and uncertainty surrounding transatlantic commitments grows, debates once viewed as non-urgent, including stronger European defense structures, are increasingly entering the mainstream. Thus, it is important to understand Ukraine’s accession in light of the EU's future geopolitical role, security capacity, and ability to strengthen the EU in an increasingly unstable international environment.

Chris Goebel, Senior Legal Advisor at the Public International Law and Policy Group

Many of the concerns surrounding “absorption capacity” or institutional readiness are real. Yet they also function as politically acceptable ways of expressing broader hesitation about enlargement itself. Reframing Ukraine’s accession as strengthening European security and strategic resilience, rather than simply expanding the Union geographically, may therefore become essential for building domestic political support.

3. Ukraine as a Security Contributor, Not Only a Security Consumer

Major General Darrell Guthrie, US Army (Ret.), PILPG Senior Peace Fellow

Ukraine’s wartime experience has fundamentally changed what it brings to the European Union. Rather than approaching accession solely through the lens of reconstruction costs or institutional burden-sharing, the discussion should also include Ukraine’s military and strategic value to Europe itself. Years of full-scale war have transformed Ukraine into one of the most operationally experienced military actors in Europe, particularly in areas such as autonomous systems, battlefield innovation, intelligence integration, drone warfare, and modern conventional combat. These are capabilities many European states are now attempting to rapidly develop themselves. 

Ukraine increasingly appears not simply as a future recipient of European security guarantees, but as a contributor to Europe’s evolving security architecture, capable of strengthening the Union strategically, politically, and institutionally.

Chris Goebel, Senior Legal Advisor at the Public International Law and Policy Group

This shift intersects directly with broader debates surrounding European strategic autonomy. In countries such as France, discussions about strengthening Europe’s independent defense capacity have intensified amid uncertainty surrounding long-term American commitments to European security.

In that context, Ukraine’s military experience and defense innovation increasingly appear less as liabilities and more as strategic assets. Ukraine’s accession therefore becomes tied not only to enlargement policy, but also to wider debates about Europe’s future defense coordination and geopolitical resilience.

Greta Ramelli, Legal Officer, Program Manager at the Public International Law & Policy Group

Public conversations surrounding European security have already begun shifting. Ideas previously viewed as politically unrealistic, including stronger collective European defense structures, are increasingly entering mainstream debate. Ukraine’s accession now unfolds against this broader reassessment of Europe’s security infrastructure.

Ambassador Zorica Marić-Djordjević, former Head of the Permanent Mission of Montenegro to the World Trade Organization and Special Representative of Montenegro to the UN Human Rights Council

Ukraine’s accession debate also raises a deeper question about the European Union’s own security capacity. While Article 42.7 of the Treaty on European Union is often discussed as a potential security guarantee for Ukraine, its practical credibility would depend on far greater operational clarity and institutional preparation than currently exist. Questions surrounding the scope of assistance, coordination mechanisms, force generation, and the interaction between EU and NATO structures remain only partially resolved.

Russia’s war against Ukraine has therefore exposed not only the geopolitical importance of enlargement but also the limits of the European Union’s current defense architecture. In practice, Ukraine’s long-term security would likely continue to depend heavily on NATO capabilities, American strategic support, and bilateral security arrangements unless the EU moves toward substantially deeper defense integration.

4. Could Ukraine’s Accession Transform the European Union Itself?

Kateryna Kyrychenko, Head of Ukraine Legal Affairs and Program Management at the Public International Law and Policy Group

Russia’s full-scale invasion has exposed structural limitations within the European Union itself. Many EU institutional mechanisms were designed for a significantly less tense and confrontational geopolitical environment, one in which large-scale interstate war on the continent appeared unlikely. The war has highlighted weaknesses in areas such as defense coordination, strategic decision-making, and unanimity requirements, particularly where individual member states can obstruct sanctions, military assistance, or broader foreign policy responses.

Ukraine’s candidacy may therefore become a catalyst for long-discussed institutional reforms inside the Union itself. Rather than simply adapting Ukraine to Europe, the accession process may increasingly require Europe to adapt to a fundamentally different strategic environment.

Stephanie Gusching⁩, Associate at White & Case, secondee at the Public International Law and Policy Group

Ukraine’s accession also presents Europe with a broader geopolitical opportunity. At a moment of growing geopolitical fragmentation, the European Union has an opportunity to demonstrate political cohesion and strategic leadership. In this sense, enlargement becomes tied not only to Ukraine’s future, but also to Europe’s broader role within an increasingly unstable international system.

Chris Goebel, Senior Legal Advisor at the Public International Law and Policy Group

Concerns about accelerated accession are tied to broader debates within the EU itself, particularly in countries such as France and Germany, where fears about institutional dilution remain strong. Calls for treaty reform before enlargement often reflect concerns about preserving political balance inside the Union.

In this context, phased integration may offer a more politically realistic path forward. Political commitment and strategic integration could move ahead earlier, while technical harmonization continues over time. This would not be entirely unfamiliar to the EU, which has long operated through different speeds and levels of integration across policy areas. Ukraine’s accession is becoming part of a much larger conversation about Europe’s future security role, strategic autonomy, and institutional development.

Ambassador Joachim Rücker, former Special Representative of the UN Secretary-General and Head of the UN Mission in Kosovo

Recent discussions inside the European Union suggest that the political understanding of “extraordinary accession” may itself be evolving. While many European leaders increasingly recognize the geopolitical exceptionalism of Ukraine’s candidacy, the emerging consensus appears less focused on immediate accession followed by phased integration, and more on accelerated phased integration as a bridge toward eventual full membership.

This approach appeared to gain traction during the April informal European Council discussions in Cyprus. Under such a model, the “extraordinary” nature of Ukraine’s accession would lie not in bypassing the accession process altogether, but in creating unprecedented forms of early integration prior to formal membership. German Chancellor Friedrich Merz publicly outlined elements of this approach, including closer Ukrainian participation in EU institutions, gradual integration into specific policy areas depending on reform progress, and discussions surrounding a possible form of “associated membership” that would grant Ukraine significantly greater institutional participation before full accession. According to proposals reportedly circulated among EU leadership, such a status could include participation in meetings of the Council of the European Union and the European Council, phased integration into parts of the EU budget and institutional framework, and, most significantly, the possible extension of the EU’s mutual assistance and defense clause to Ukraine. Such arrangements could also require greater use of differentiated integration mechanisms within the EU itself.

The discussion is also beginning to extend beyond Ukraine alone. In February 2026, Albanian Prime Minister Edi Rama and Serbian President Aleksandar Vučić jointly proposed that EU candidate states should gain earlier access to structures such as the internal market and the Schengen area before full accession. Such proposals suggest that phased integration may increasingly emerge as part of a broader rethinking of enlargement during a period of geopolitical instability.

For Ukraine and its partners, this may carry an important strategic implication: if phased integration is becoming the politically realistic pathway, the focus may increasingly turn toward maximizing the substance and political significance of these intermediate stages. Proper political framing will be essential to ensure that phased integration is understood not as postponement, but as irreversible strategic anchoring within the European Union.

Ambassador Zorica Marić-Djordjević, former Head of the Permanent Mission of Montenegro to the World Trade Organization and Special Representative of Montenegro to the UN Human Rights Council

The Western Balkans remain an important reference point in discussions surrounding Ukraine’s accession, particularly as a reminder of how enlargement processes can become stalled by bilateral disputes, veto politics, and enlargement fatigue despite formal EU commitments to accession. Ukraine’s trajectory has differed markedly in speed and political prioritization, reinforcing the sense that the European Union increasingly views Ukraine’s accession not solely as a technocratic process, but as part of a broader strategic and security imperative.

5. The Strategic Risks of Delay

Dr. David Crane, Founding Chief Prosecutor of the UN Special Court for Sierra Leone and Founder of the Global Accountability Project

Delay itself carries geopolitical consequences. Prolonged hesitation risks reinforcing the very strategy the Russian state has pursued throughout the war: exploiting distraction, exhausting political attention, and relying on institutional caution to slow European decision-making. Time becomes part of the strategy.

Europe may already recognize the broader geopolitical logic behind Ukraine’s accession, yet still remain reluctant to translate that logic into political action. A lengthy accession process risks creating exactly the kind of uncertainty and drift that Russia has consistently sought to preserve.

Prof. Milena Sterio, the Joseph C. Hostetler-BakerHostetler Professor of Law at Cleveland State University College of Law and Managing Director at the Public International Law and Policy Group  

The current moment may ultimately require forms of political creativity that the EU has historically been reluctant to embrace. Accelerated political integration would not eliminate the need for reforms, technical harmonization, or institutional adaptation. But it would require treating accession as part of Europe’s broader security response, rather than as a process insulated from the war that made the question so urgent.

Kateryna Kyrychenko, Head of Ukraine Legal Affairs and Program Management at the Public International Law and Policy Group 

The broader danger lies in treating prolonged ambiguity as a neutral or stabilizing outcome. Leaving Ukraine outside durable European structures would not freeze the geopolitical situation in place; it would preserve a space of continued vulnerability and instability on Europe’s eastern border.

At this stage, the debate is no longer only about technical readiness or procedural sequencing. Russia’s war against Ukraine has already exposed the limits of many assumptions on which Europe’s post-Cold War security order was built. The question now is whether the European Union is prepared to respond to that changed reality, including by adapting mechanisms that were designed for a far less confrontational environment.

Ukraine’s accession has therefore become tied to a much broader issue: how Europe defines its own future in a period of sustained geopolitical confrontation.

Ambassador Zorica Marić-Djordjević, former Head of the Permanent Mission of Montenegro to the World Trade Organization and Special Representative of Montenegro to the UN Human Rights Council

Another strategic risk lies in tying Ukraine’s European future to broader peace negotiations. While EU accession formally remains a sovereign process governed by EU criteria, prolonged diplomatic bargaining could create informal pressure to slow or condition integration in exchange for ceasefires, sanctions relief, or broader settlement arrangements. Maintaining a clear separation between accession and territorial bargaining may therefore become essential for preserving both the credibility of enlargement policy and Ukraine’s sovereign political choices.

Concluding Observations

The discussion reflected a growing sense that Ukraine’s accession debate has entered a fundamentally different phase. The central question is no longer simply whether Ukraine belongs within the European Union, but whether the Union itself is capable of responding politically to the strategic realities created by Russia’s war.

A widening gap remains between Europe’s geopolitical rhetoric and the procedural caution that continues to define enlargement policy in practice. While a few contributors dismissed the importance of reforms, institutional balance, or domestic political constraints, many questioned whether existing accession frameworks were designed for circumstances of this magnitude. In that sense, the debate surrounding “extraordinary accession” ultimately became a broader debate about the EU’s capacity for political adaptation during a crisis.

At the same time, the discussion suggested an important shift in perspective: Ukraine is increasingly viewed not only as a state seeking integration into Europe, but as a country already reshaping Europe’s understanding of security, defense, and strategic resilience. Rather than existing at the margins of Europe’s future, Ukraine has become central to many of the debates now redefining it.

Whether the European Union ultimately chooses a conventional accession path or develops more flexible political mechanisms, delay is not a neutral policy choice. The longer uncertainty persists, the more difficult it becomes to separate enlargement policy from the wider geopolitical contest unfolding across Europe itself.

PILPG Roundtable Blog Part I: Ukraine’s EU Accession: Perspectives of Enlargement During the War

PILPG Roundtable Blog 

Part I: Ukraine’s EU Accession: Perspectives of Enlargement During the War

Editor’s Note

This roundtable explores one of the most consequential strategic questions facing Europe today: Ukraine’s accession to the European Union amid an ongoing war of aggression. Building on discussions within the Public International Law & Policy Group (PILPG) Ukraine Peace Negotiations Working Group, this piece brings together expert perspectives on how enlargement policy is being reshaped by geopolitics, security imperatives, and the pursuit of a just and durable peace.

Presented under the Lawyering Peace initiative, this roundtable situates EU accession not merely as a technical legal process, but as a defining test of Europe’s political will and strategic identity. As Ukraine continues to defend itself, its European trajectory has become inseparable from broader questions of deterrence, stability, and the future of the European project itself.

On 10 April 2026, members of PILPG’s Ukraine Peace Negotiations Working Group convened to assess the evolving trajectory of Ukraine’s EU accession process. More than a decade after the Maidan protests set Ukraine on its European path, accession now unfolds under radically different conditions: amid full-scale war, shifting transatlantic dynamics, and renewed debates about Europe’s strategic autonomy.  

1. How should Ukraine’s EU accession be framed: as a technical enlargement process or as a strategic security imperative?

Dr. David Crane, Founding Chief Prosecutor of the UN Special Court for Sierra Leone and Founder of the Global Accountability Project

EU accession, in this context, stops being a checklist exercise and becomes something much sharper: a strategic decision about what Europe is prepared to stand for. One of the recurring themes in the discussion was that enlargement is among the few tools entirely in the EU’s hands. Using it decisively would send a message that is difficult to misinterpret, both to Moscow and to Europe’s own partners.

There is also a timing element. Moving forward now, rather than waiting for a more “convenient” moment, would signal that aggression does not freeze political integration. It also risks allowing Ukraine’s European trajectory to become implicitly negotiable in broader political or diplomatic processes, which is something that would fundamentally undermine its sovereignty. In that sense, the discussion also pointed toward the need for more flexible or even exceptional approaches to accession that reflect the realities of the current moment, rather than relying exclusively on peacetime models.

Chris Goebel, Senior Legal Advisor at PILPG

There was a clear sense that the EU is still speaking in two registers at once. On the one hand, Ukraine’s membership is framed politically as inevitable. On the other, the day-to-day discourse remains highly technical, concerning criteria, sequencing, absorption capacity.

The tension between those two narratives is becoming harder to sustain. Concerns about budgetary impact or institutional readiness are real, but they are being asked to carry too much weight. At some point, they need to be placed within a broader strategic frame, rather than quietly dictating the pace of the process.

Ambassador Joachim Rücker, former Special Representative of the UN Secretary-General and Head of the UN Mission in Kosovo

What has shifted, perhaps more than anything else, is the baseline. The question is no longer whether Ukraine belongs in the EU, but how quickly and through which mechanisms that can be realized. Recent discussions among foreign ministers suggest that this is now broadly understood across member states.

That does not mean there is agreement on method. But it does mean that enlargement in this case is no longer treated as routine. The legal framework has remained unchanged; the political context around it has not.

Ambassador Zorica Marić-Djordjević, former Head of the Permanent Mission of Montenegro to the World Trade Organization and Special Representative of Montenegro to the UN Human Rights Council

From a Western Balkans perspective, the risks of ambiguity are well known. When accession becomes slow, uncertain, or overly procedural, it stops stabilizing and starts producing frustration and drift.

In Ukraine’s case, that dynamic would be far more dangerous. Prolonged uncertainty along the EU’s eastern border is not a neutral outcome. It creates space for continued pressure, whether political, hybrid, or military. That is why enlargement here cannot be treated as business as usual, it has become part of Europe’s security policy in a very direct sense. As with earlier rounds of enlargement, integration serves to anchor stability over the long term and should not be allowed to become contingent on short-term political bargaining.

Any model of integration that introduces prolonged uncertainty or second-tier status would risk undermining that strategic function rather than reinforcing it.

Greta Ramelli, Legal Officer, Program Manager at the Public International Law & Policy Group

One constraint that keeps coming up, implicitly more than explicitly, is the domestic political one. Even where governments are aligned, public opinion is uneven. There is still a gap between elite consensus and what voters across the EU are prepared to support. Closing that gap will require a different kind of argument. Not just solidarity with Ukraine, but a clearer articulation of what accession delivers for the EU itself in different areas - economically, politically, and in terms of long-term independence.

Kateryna Kyrychenko, Head of Ukraine Legal Affairs and Program Management at the Public International Law and Policy Group

From the Ukrainian perspective, accession cannot be separated from the broader political and historical context of the war itself. Ukraine’s European course was not adopted opportunistically during the war, it became one of the central triggers of Russian aggression long before the full-scale invasion. The 2014 Revolution of Dignity and the Association Agreement process reflected a societal choice in favor of sovereignty, democracy, and integration with Europe. In that sense, Ukraine’s accession increasingly concerns more than technical compliance with accession criteria. It raises a broader question of whether the European Union views enlargement primarily as an administrative process or as a strategic instrument capable of responding to existential security challenges on the continent.

At the same time, prolonged uncertainty carries risks of its own. Leaving Ukraine in a prolonged geopolitical “grey zone” would not preserve stability, but instead sustain the very vulnerability and pressure that Russia has consistently sought to exploit.

2. What are the real political obstacles among member states to accelerating Ukraine’s accession and how can they be addressed?

Chris Goebel, Senior Legal Advisor at PILPG

The obstacles are not hidden, they are just often framed differently. “Absorption capacity,” budget concerns, and institutional balance, for example, are all real issues, but they also function as politically acceptable ways of expressing hesitation.

France was mentioned as a useful example: strongly supportive of Ukraine, but careful to anchor that support in a strictly merit-based process. That position is defensible, but it also slows things down in practice. The challenge is how to reconcile that caution with the strategic urgency that many of the same actors acknowledge.

Narratives within member states matter just as much as formal positions. Where enlargement is framed as a risk, it becomes politically costly; where it is framed as an opportunity, space opens up. Reframing Ukraine’s accession in terms of the areas it can contribute to (such as security, economic resilience, strengthening Europe’s global position) will be essential to shifting that balance.

Ambassador Joachim Rücker, former Special Representative of the UN Secretary-General and Head of the UN Mission in Kosovo

Legally, there is very little standing in the way. Article 49 remains the basis, and within it there is more flexibility than is sometimes admitted, for example with transitional phases, sequencing, differentiated timelines.

So the conversation ultimately returns to political will. If the decision is made to move faster, the legal tools are already there. If not, they will not move the process forward on their own.

Ambassador Zorica Marić-Djordjević, former Head of the Permanent Mission of Montenegro to the World Trade Organization and Special Representative of Montenegro to the UN Human Rights Council

Enlargement has never been purely technical, even if it is often presented that way. The Western Balkans experience shows how easily the process can become opaque and drawn out when political commitment weakens.

Ukraine’s case exposes that dynamic quite clearly. The framework allows for flexibility; the question is whether it will be used. Without that, references to criteria and procedures risk substituting for decision-making rather than guiding it. 

Part of the response also lies on the Ukrainian side. Addressing known pressure points such as minority rights, rule of law, and institutional reform early and visibly can help neutralize resistance that tends to emerge in later stages. This is not simply about compliance, but about shaping the political environment in which decisions are made.

At the same time, however, the decisive factor at this stage lies with the European Union itself. Enlargement has always been driven as much by political determination as by technical readiness. A clear political decision to advance Ukraine’s accession would not bypass the criteria, but it would define the pace, sequencing, and credibility of the process. Without that signal, even substantial reform progress risks being absorbed into procedural delay. With it, the accession framework can operate as intended as a structured pathway toward integration, rather than an open-ended process that risks creating a sense of permanent limbo and eroding both credibility and momentum.

Dr. David Crane, Founding Chief Prosecutor of the UN Special Court for Sierra Leone and Founder of the Global Accountability Project

A broader point concerned the shifting international environment. Europe can no longer assume that its security framework will look the same as it has over the past decades. That reality should inform how decisions like enlargement are approached.

Waiting for alignment elsewhere may no longer be a viable strategy. In that sense, Ukraine’s accession is as much about Europe defining its own direction as it is about Ukraine joining. This opens the door to genuinely unconventional approaches to enlargement. Treating Ukraine as an exceptional case, where political commitment precedes full technical completion, reflects a growing recognition that existing models may not fully capture the realities of accession during wartime.

Greta Ramelli, Legal Officer, Program Manager at the Public International Law & Policy Group

Ultimately, this comes back to communication. If citizens across the EU do not see how Ukraine’s accession aligns with the Union’s core promises (prosperity, stability, security) support will remain fragile, regardless of elite consensus.

3. What model of phased or partial integration is most viable for Ukraine and what are the risks

Ambassador Joachim Rücker, former Special Representative of the UN Secretary-General and Head of the UN Mission in Kosovo

Phased integration is often presented as the practical compromise, allowing progress without forcing an immediate all-or-nothing decision. There is logic to that, particularly given the scale of the challenge.

At the same time, not all precedents translate well. The Cyprus model is often cited, yet its applicability is limited. Extending it (i.e. by admitting more members with unresolved territorial issues) raises broader political questions, not only for Ukraine but for other unresolved territorial situations in Europe. This makes the issue less a legal problem and more a political one, with implications beyond a single case.

Ambassador Zorica Marić-Djordjević, former Head of the Permanent Mission of Montenegro to the World Trade Organization and Special Representative of Montenegro to the UN Human Rights Council

The risk with phased approaches is not the concept itself, but how it is implemented. If it becomes open-ended, or if full membership feels perpetually out of reach, it can erode both credibility and political momentum.

That is something the Western Balkans know well. Any interim model for Ukraine would need to be clearly structured, time-bound, and visibly moving toward full integration, not replacing it.

Ukraine’s situation is fundamentally distinct. Any approach will need to reflect the reality of ongoing aggression while avoiding the creation of precedents that could complicate other regional dynamics.

Dr. David Crane, Founding Chief Prosecutor of the UN Special Court for Sierra Leone and Founder of the Global Accountability Project

There was also openness to more unconventional approaches. The idea of treating Ukraine’s accession as an exceptional case that includes moving politically first and resolving technical questions in parallel, would reflect the sense that existing models may not fully capture the current moment.

Whether such an approach is politically feasible is another question, but it illustrates how far the discussion has moved beyond standard enlargement thinking.

Concluding Observations

What emerges from the discussion is not a single answer, but a clear shift in perspective. Ukraine’s accession is no longer a conventional enlargement question. It sits at the intersection of security, political will, and the future shape of the European project.

Across the contributions, one point stands out: the legal framework is not the constraint. The flexibility exists. The real variable is whether member states are prepared to act on the strategic logic they already acknowledge. The risks of delay are not neutral. Prolonged ambiguity weakens credibility, invites instability, and allows external actors to shape the terms of Ukraine’s future. By contrast, a clear and politically anchored accession trajectory would reinforce Europe’s capacity to act decisively in a contested geopolitical environment.

Ultimately, Ukraine’s accession has become a test case. Not only for enlargement policy, but for whether the European Union can adapt its instruments to the realities of war and strategic competition. The outcome will signal far beyond Ukraine itself.

Extraordinary Accession: Why Europe Must Bring Ukraine into the European Union Now

Extraordinary Accession: Why Europe Must Bring Ukraine 

into the European Union Now

by David M. Crane* 

Executive Summary 

Europe stands at a geopolitical crossroads. Russia’s full-scale aggression against Ukraine has shattered the illusion that the post-Cold War order could be preserved through incrementalism, dialogue, or strategic ambiguity. Moscow is betting quite openly that Europe will hesitate, delay, and ultimately retreat from the historic question of Ukraine’s membership in the European Union. The Kremlin’s strategic calculation is simple: Europe will not bring Ukraine into the EU in the short or medium term, regardless of political declarations or symbolic gestures such as the Foreign Ministers’ meeting in Kyiv in March 2026. 

This policy paper argues the opposite. Europe must bring Ukraine into the European Union now - not as a conventional accession, not as a “fast track,” but as an extraordinary accession that recognizes the singular nature of Ukraine’s struggle and the existential stakes for Europe itself. Political membership should be granted immediately, with the technical and treaty-based obligations phased in over time. This is not only feasible; it is strategically necessary. 

Ukraine’s accession would send an unmistakable signal to Russia and the international community: Ukraine is Europe - permanently, irreversibly, and without qualification. 

The Strategic Context: Russia’s Bet on European Hesitation 

Russia’s war is not only a military campaign; it is a long-term strategy aimed at fracturing European unity and undermining the credibility of Western institutions. Central to this strategy is the belief that: 

• Europe will not take bold political steps that carry risk;

• The EU will cling to procedural orthodoxy rather than geopolitical necessity; 

• Ukraine will remain in a gray zone - supported, admired, but not integrated. 

This belief is reinforced by decades of European caution, slow enlargement processes, and internal debates over institutional reform. Even the March 2026 Foreign Ministers’ meeting in Kyiv, historic in symbolism, has not convinced Moscow that Europe is prepared to act decisively. 

Extraordinary accession is the only response that breaks this strategic calculus.

Why Ukraine’s Accession Is Not a “Fast Track”, It Is a Different Category Entirely 

Traditional EU accession is designed for states transitioning peacefully toward European norms. Ukraine is not in that category. It is: 

1. a state defending Europe’s security architecture on the battlefield;

2. a democracy proving its resilience under existential threat; 

3. a society already aligned with European values through sacrifice, not just legislation. 

Ukraine’s accession should therefore be understood as as encompassing any and all of the following: 

1. A political act of continental self-defense: bringing Ukraine into the EU strengthens Europe’s collective security, deters further Russian aggression, and stabilizes the eastern frontier. 

2. A moral recognition of Ukraine’s role in defending European values: no candidate state has ever demonstrated its commitment to democracy, rule of law, and human dignity more clearly or at greater cost. 

3. A strategic investment in Europe’s long-term stability: a secure, integrated Ukraine anchors the Black Sea region, strengthens energy diversification, and expands Europe’s economic and demographic base. 

4. A precedent for extraordinary circumstances, not a shortcut for ordinary candidates: this is not a dilution of standards; it is an acknowledgment that Ukraine’s situation is unique in modern European history. 

A Two-Track Accession Model: Political Membership Now, Technical Integration Over Time

To reconcile urgency with institutional integrity, the EU could consider adopting a two-track accession model: 

Track 1: Immediate Political Membership 

Ukraine becomes a full political member of the European Union with the representation in the European Parliament, a seat on the European Council, participation in EU foreign policy and security decision-making and access to EU political institutions and voting rights (with transitional arrangements as needed).

This step sends the decisive geopolitical signal: Ukraine is in Europe, and Europe stands with Ukraine. 

Track 2: Phased Implementation of Treaty Obligations 

Over a defined period, negotiated jointly, Ukraine would progressively adopt: 

• The acquis communautaire;

• Single market regulations;

• Judicial and administrative reforms; 

• Economic convergence measures; 

• Environmental and agricultural standards;

• Customs and border integration. 

This phased approach mirrors the EU’s own history of differentiated integration and acknowledges the realities of wartime governance. 

Why Extraordinary Accession Serves Europe’s Interests 

There are at least 5 arguments here:

1. It restores credibility to the European project: for years, the EU has been criticized for strategic timidity. Extraordinary accession demonstrates that Europe can act with purpose when history demands it. 

2. It strengthens deterrence: Russia’s aggression thrives on ambiguity. Ukraine’s accession eliminates the gray zone that Moscow exploits. 

3. It stabilizes Europe’s eastern frontier: a politically integrated Ukraine becomes a pillar of European security, not a buffer state. 

4. It accelerates reconstruction and economic integration: EU membership unlocks investment, reduces corruption incentives, and anchors reforms in a durable institutional framework. 

5. It reinforces the global rule-of-law order: Ukraine’s accession signals that borders cannot be changed by force and that democracies under attack will not be abandoned. 

Addressing the Concerns: Why Extraordinary Accession Is Manageable 

Concern 1: Institutional capacity

The EU has repeatedly adapted to enlargement. Transitional voting arrangements, phased integration, and opt-ins/opt-outs are well-established tools. 

Concern 2: Economic disparities 

Phased implementation of the acquis and targeted reconstruction funds can manage convergence without destabilizing existing members. 

Concern 3: Security risks 

Ukraine’s battlefield experience and intelligence capabilities strengthen, not weaken, European security. 

Concern 4: Precedent for other candidates 

The EU can clearly articulate that extraordinary accession applies only to states defending Europe against existential aggression. 

Conclusion: A Defining Choice for Europe 

Europe has reached a moment where hesitation carries greater risk than action. Ukraine’s accession is not merely a bureaucratic process; it is a strategic imperative and a moral obligation. It is the clearest possible signal to Russia that the era of spheres of influence is over and that Ukraine’s European future is non-negotiable. 

By granting Ukraine extraordinary political membership now, with technical obligations phased in over time, the European Union affirms its identity as a community of values, not just a market, and demonstrates that aggression will never dictate Europe’s future. 

Ukraine is Europe. The time to formalize that reality is now. 

* David M. Crane is a PILPG Peace Fellow and global leader in international criminal justice and the founding Chief Prosecutor of the UN Special Court for Sierra Leone. He has spent decades shaping accountability mechanisms around the world, including serving as a driving architect behind the Special Tribunal for the Crime of Aggression against Ukraine. Crane is a distinguished scholar of international law, a former senior U.S. national security official, and a leading voice on the rule of law, state responsibility, and the legal limits on the use of force.

Roundtable Blog: After the Rupture: International Lawyers Reckon with the Disruption of the Rules-Based Order

Roundtable Blog:

 After the Rupture: International Lawyers Reckon with the Disruption of the Rules-Based Order 

Editor’s Note

This post is part of the PILPG Lawyering Peace working group series. It presents a curated set of expert reflections drawn from a roundtable discussion held in March 2026.  The experts examine one of the most consequential questions in contemporary international affairs: whether the post-1945 rules-based international order is experiencing a temporary disruption or a fundamental, potentially irreversible rupture. The roundtable also contributes to a forward-looking policy conversation: what can international lawyers, policymakers, and civil society do to adapt or respond.

A simple question was discussed at the outset: Are we overreacting?  What followed was, rather than a debate, an agreement among experienced international lawyers and policymakers, coalescing into an unambiguous no.  The more troubling possibility, several experts suggested, is that the world has not yet grasped the full magnitude of what is already underway.

Drawing on the diverse expertise of our Peace Fellows, this post moves beyond the immediate headlines and examines the structural forces at work, characterizing the moment, tracing its causes, and asks what international lawyers, policymakers, and middle powers can realistically do in response.  Published under the Lawyering Justice banner, this post reflects our commitment not only to chronicling the legal and diplomatic dimensions of active conflicts, but also to fostering strategic foresight and connecting lawyering to policy planning. We hope this format will serve as a model for future collaborative work on peace and justice.

Characterizing the Moment

Before addressing causes, consequences, or responses, the working group spent considerable time on a terminological question that turned out to carry real analytical weight: is what is happening a paradigm shift, an evolution from one coherent order to another? or something more sudden and less legible?

Dr. David Crane, Founding Chief Prosecutor of the UN Special Court for Sierra Leone and Founder of the Global Accountability Project

Dr. Crane opened with a rejection of the premise embedded in the question. “We are not overreacting,” he said. “I am not sure what overreacting even means in this day and age.” He reached for the image of a kaleidoscope: a change in which, when one element shifts, everything simultaneously reconfigures.  The scale of the disruption, in his reading, places us at or near a threshold that previous generations associated with world war. “We are on the verge of World War III,” he said, “or we can argue it has already begun.”  The implication is not panic, rather a call for clear-eyed urgency.  Dr. Crane emphasized the need to think about how we keep ahead of the paradigm shift, through patience and scholarship.

Ambassador Jorge Lomonaco, former Ambassador of Mexico to the UN Human Rights Council and to the Organization of American States 

Ambassador Lomonaco pushed back on the premise of the opening question.  The concern, in his view, is not that the international community is overreacting to current events but that it has not yet fully reckoned with their scale.  The situation is considerably worse than most have yet grasped.  Later in the session he returned to the terminological debate with a precision that reframed the entire discussion.  A paradigm shift, he argued, implies that something new is already taking shape to replace what is being lost.  

History offers examples such as the shift from the multipolar European order to the bipolar Cold War, or from the Cold War to the post-1991 moment of American primacy.  In each case, the contours of the successor arrangement became visible relatively quickly.  What the world is facing today is different.  The post-1945 order has not shifted toward something recognizable; it has fractured, and nothing coherent has yet emerged to take its place.  In other words, “the paradigm is broken,” he said.  That distinction, between a shift and a rupture, carries real consequences for how policymakers and legal practitioners should respond.  Planning for a transition assumes a destination.  Planning for a rupture requires a different kind of thinking entirely.

Ambassador Keith Harper, former US Ambassador to the UN Human Rights Council

Ambassador Harper refined the terminology directly.  “I don’t know if it is a paradigm shift so much as a rupture of the paradigm,” he said. “The question is what replaces it.”  For Ambassador Harper, that question is not rhetorical.  He pressed the group toward a longer historical view, drawing on two of the twentieth century’s great moments of deliberate institutional construction.  The first was the preparatory work that preceded the Paris Peace Conference of 1919, where Woodrow Wilson and a team of lawyers, academics, and diplomats spent months drafting proposals for what a post-war international order should look like before a single negotiation had begun.  That preparation produced the blueprint for the League of Nations. 

The second was the drafting of the UN Charter in 1945, where Allied powers translated the wreckage of World War II into a new architecture of collective security, international law, and multilateral cooperation.  Ambassador Harper’s point was that neither of those moments happened by accident.  They were the product of deliberate, advanced thinking about what kind of world the next generation of states wanted to inhabit.  His argument was that this moment calls for exactly that kind of effort again: a serious, forward-looking rethinking of how multilateral institutions should be designed, how alliances should be structured, and what shared rules should govern a world that looks nothing like the one those earlier architects faced.  His hope is that American politics will ultimately recognize the current trajectory for what it is and that space will reopen to do that work alongside allies.

The American Recalibration: Cause or Symptom?

The Trump administration’s reorientation of American foreign policy is the most visible driver of the current disruption.  But several experts pressed a harder question: is the US the cause of the rupture, or the symptom of forces that would have produced it regardless?

Ambassador Julian Braithwaite, former British Ambassador to the WTO, UN, and Other International Organizations in Geneva

Ambassador Braithwaite traced a line through three successive Western military interventions in the Middle East, each one revealing something about the state of the international order at the moment it occurred.  The 1991 Gulf War, launched in response to Iraq’s invasion of Kuwait, was authorized by the UN Security Council and assembled one of the broadest multilateral coalitions in the post-war era.  It represented the rules-based order functioning close to its intended design: collective authorization, shared burden, declared objectives. 

The 2003 invasion of Iraq showed a more complicated picture.  The legal basis was disputed, the coalition was narrower, and the objectives became increasingly difficult to define as the conflict deepened.  But the US and its partners still operated within a framework of justification, however contested, and still sought to build an international rationale for what they were doing.  

The current situation represents something categorically different.  For instance, the current US-Israeli invasion of Iran is neither accompanied by a UN Security Council resolution, nor a justification or alliance.

What that sequence reveals, he argued, is not simply a change in American behavior under a particular administration but a structural trend that has been building for decades, and that is the progressive erosion of the multilateral architecture that once gave military action its legitimacy.  The rules-based international order was never a purely principled construction.  It was built to serve interests and it functioned because powerful nations were willing to act as the enforcer of last resort when the system’s norms were violated.   As the costs of that role grew and the domestic political appetite for it diminished, the system began hollowing out from within.  Without the state that designed and underwrote it, the architecture does not simply weaken, it atrophies.

Dr. Igor Lukšić, Former Prime Minister and Foreign Minister of Montenegro

To Dr. Lukšić, the absence of UN Security Council authorization for major military action is not a new phenomenon.  The historical record reflects a pattern in which the use of force has often proceeded outside the Charter framework, with outcomes shaped heavily by prevailing geopolitical dynamics.  The US-led military intervention in Korea in 1950 was formally enabled by a Security Council mandate secured only because of the Soviet Union’s temporary boycott; the 1999 NATO intervention in Yugoslavia unfolded without any Council authorization; and the 2003 US invasion of Iraq proceeded without explicit UNSC authorization, justified instead through contested claims about weapons of mass destruction and existing UNSC resolutions. 

By contrast, the response to Iraq’s invasion of Kuwait in 1990 did receive Security Council approval.  In many cases, military action undertaken outside the Council’s prior authorization was later followed by Security Council engagement or resolutions addressing the evolving situation.  The current situation, where military force is being deployed outside the framework the UN Charter was designed to provide, is not, on that dimension alone, historically unprecedented.

What is different, and what makes the present moment genuinely novel, is the simultaneous layering of multiple crises across different regions and domains, combined with a pace of change that is outrunning the capacity of institutions and governments to respond coherently.  The world, in his framing, has moved past the era of clear American primacy that defined the post-Cold War decades, but it has not arrived anywhere new.  It occupies an unstable in-between, it is no longer unipolar, not yet genuinely multipolar, and without an agreed framework for managing the competition that fills the space between those two conditions.  Dr. Lukšić was candid about the limits of what anyone can predict from this position.  The process of finding a new equilibrium will be long and structurally disruptive, he emphasized. “It will be a painful process that will lead to something, what exactly is hard to say, but it will have to be another rules-based order.”

Speed, Enforcement, and the Deliberate Demolition

Ambassador Elizabeth Richard, former US Ambassador to Lebanon & Coordinator for Counterterrorism / Ambassador at-Large

What the international community is witnessing, Ambassador Richard argued, is not improvised disruption but a deliberately designed strategy, and its central instrument is speed.  The logic she described is one that anyone familiar with legal and institutional processes will recognize: rules-based systems, whether domestic courts, international tribunals, or multilateral bodies, operate on timelines.  Investigations take months.  Litigation takes years.  Treaty renegotiation takes longer still.  When governments move faster than those timelines, they can reshape facts on the ground before any accountability mechanism has had time to engage.  Withdrawal from international agreements, defunding of multilateral institutions, reassignment of treaty obligations, restructuring of alliances, each of these actions is considerably easier to execute than it is to reverse, and that asymmetry between dismantling and rebuilding is not incidental. 

It is, in Ambassador Richard’s reading, the defining feature of the current moment. “Eventually the law may catch up, but by the time it does, you cannot put the pieces back together again.”  That observation raises a question she left deliberately open: if the space vacated by retreating multilateral engagement cannot be reclaimed through legal or institutional challenge in real time, can a coalition of middle powers construct and enforce a values-based alternative before that space is filled by something else entirely? 

States like Canada, the UK, Germany, Japan, and Australia individually lack the singular weight of a great power, but collectively they represent significant diplomatic, economic, and normative influence.  The question is whether that influence can be organized quickly enough and with sufficient coherence to matter.

Major General Darrell Guthrie, US Army (Ret.)

In agreement with Ambassador Richard, the compression of decision-making timelines is not simply a political phenomenon, Guthrie argued.  It is structural, and it has been accelerating for decades.  Financial markets now execute transactions in fractions of a second.  Information travels across the globe instantaneously.  Corporate decisions that once required weeks of deliberation are made in hours.  The private sector adapted to that reality long ago, redesigning its institutions, its processes, and its expectations accordingly.  However, the international governance system has not.  The UN Security Council still deliberates.  International courts still move through years of procedure.  Treaty bodies still require consensus among dozens of states before anything binding can be agreed.  Those processes were designed for a world where the pace of events allowed for reflection, negotiation, and incremental adjustment.  That world no longer exists. “An international rules-based order was premised on time,” Guthrie said.   

The result is a structural imbalance. Those whose power depends on deliberation and consensus are increasingly disadvantaged, while those willing to treat speed as a strategic instrument gain the upper hand. Institutions that cannot keep pace with the challenges they were built to address do not simply become less effective. They get bypassed altogether, left out of the decisions that actually shape outcomes.

Elayne Whyte-Gomez, former Ambassador and Permanent Representative of Costa Rica to the United Nations, Senior Fellow of the United Nation Institute for Disarmament Research, and Professor at Johns Hopkins School of Advanced International Studies. 

The international order, Ambassador Whyte-Gomez argued, is not simply something that powerful states construct and destroy on their own terms.  It is sustained by the willingness of the broader community of states to defend it, invoke it, and refuse to look the other way when it is violated.  When small and middle powers invoke its norms, challenge violations, and insist on accountability, the order retains its functional weight even when the most powerful actors strain against it.  When they go silent, or worse, retreat into vague diplomatic language designed to offend no one and commit to nothing, the order loses the constituency that gives it life.  “The international order does not cease to exist by the actions or the narrative of powerful actors alone,” she said.  “It ceases to exist when the rest, such as experts and middle and small nations, acquiesce.” 

What concerned Ambassador Whyte-Gomez was precisely that pattern of acquiescence beginning to take hold.  States that might otherwise serve as normative anchors are increasingly issuing statements carefully calibrated to avoid confrontation, offering wishy-washy expressions that say nothing.  The pressure to accommodate is real and understandable, she acknowledged, but she drew a sharp distinction between principled restraint and silence.  A state that chooses not to speak when the rules it has long championed are being dismantled is not staying neutral.  It is making a choice, and that choice has consequences for the durability of the very framework it depends on.

Ambassador Whyte-Gomez then placed the current moment in a longer historical frame.  She drew on two precedents where deliberate, advanced legal and political thinking produced institutions that shaped the international order for generations.  The first was the preparatory work that preceded the Paris Peace Conference of 1919, as mentioned previously in this post, where Wilson and a team of advisors spent months drafting proposals for a post-war order before negotiations began, work that ultimately produced the blueprint for the League of Nations.  The second was the drafting of the UN Charter in 1945, where the architects of the post-war order translated the lessons of catastrophic failure into a new framework for collective security and international law.  In both cases, lawyers played a central role not as technicians implementing decisions already made by politicians, but as architects of the conceptual framework within which those decisions were made. “There is a role now for lawyers,” she said.  “To stop and think.”  

Ambassador Whyte-Gomez then returned to the historical arc that Ambassador Braithwaite had opened earlier in the session and brought it to a precise conclusion.  Where Ambassador Braithwaite had traced the erosion of multilateral architecture across three decades of Western military interventions, Ambassador Whyte-Gomez identified what is categorically new about the present moment. 

Throughout the post-war period, the United States, even when acting outside the bounds of international law, maintained the practice of constructing a legal justification for its use of force and formally communicating that justification to the UN Security Council, invoking the right to self-defense pursuant to Article 51 of the UN Charter.  The justifications were sometimes thin and sometimes contested, but they existed, and their existence mattered, because they acknowledged the framework even in the act of straining against it.  They provided other states with something to engage with and challenge; they openly conveyed a vision of the situation and a shared vocabulary through which other actors could understand it and hold power to account through a formal communication process. 

The present difficulty in building a legal rationale is therefore not a minor procedural omission.  Rather, it reveals a new context for the decision-making process and the standard inter-agency contributions.  The policy process has become disarticulated from the framework itself, playing no role in the final decision.  “This,” she concluded, “is the real rupture.”

Accountability, Institutions, and the Compliance Crisis

Kateryna Kyrychenko, Head of Ukraine Legal Affairs and Program Management at PILPG

Kyrychenko’s contribution reframed the institutional discussion in a way that cut against the grain of much of what had preceded it.  “There is nothing inherently wrong with international law,” she argued.  “The real problem lies in its execution and compliance.”  She described what she called an age of “international populism,” a period in which international agreements are signed as political gestures, frequently rushed to meet symbolic deadlines or demonstrate quick diplomatic success, producing documents that are “difficult, if not impossible, to enforce.”  The politicization of international law, in her diagnosis, consistently prevails over its genuine legalization.

Her prescription looked inward: greater attention to national legislation and constitutional frameworks.  Wars are ultimately won by states, not international institutions, and the preservation of constitutional order is critically important.  Ukraine, she argued, offers a powerful example: despite more than four years of full-scale aggression, the country has continued to uphold its constitutional regime, “an achievement that deserves recognition,” demonstrating how, in practice, domestic legal resilience becomes critical where international law cannot ensure compliance.

Stephanie Gusching⁩, Associate at White & Case, secondee at PILPG

Gusching focused on the structural pathologies of the UN Security Council.  The veto mechanism has rendered the Council functionally inoperative at precisely the moments it is most needed, including with respect to Ukraine, Gaza, and Iran.  “If international law exists, we need to reimagine how these institutions operate and evolve,” she said.  Her proposals are specific: majority-based consent structures within the Council and required abstention for parties directly implicated in a conflict.  The world that produced the UN Charter in 1945 no longer exists; the institution designed for that world should not be expected to function as if it still does.

Middle Powers and the Question of What Comes Next

Dr. Williams posed the session’s most forward-looking question: when we come to this fork in the road, who chooses which way we go?  Some will say the US.  Some will say a new coalition of middle powers.  Is it possible that both paths are pursued simultaneously, the US doubling down on a constricted definition of its interests while others construct an alternative architecture?

Ambassador Jorge Lomonaco, former Ambassador of Mexico to the UN Human Rights Council and to the Organization of American States 

Ambassador Lomonaco articulated the middle power dilemma with the precision of someone who has spent decades navigating it from the inside.  For much of the post-war period, he argued, middle powers had a clear orienting framework.  They could look to a set of principles that were anchored in international law, multilateral cooperation, and the peaceful resolution of disputes, and align their foreign policy accordingly.  That alignment was not always without tension, and the principles were not always perfectly applied, but the framework itself was coherent and the direction of travel was clear.  What the current moment has disrupted is not simply the application of those principles but the willingness of the state that underwrote them to continue doing so.  That leaves middle powers in genuinely uncharted territory.  Aligning with a world order stripped of the principles that once gave it legitimacy is not an attractive option.  Aligning with an alternative order built around spheres of influence and the primacy of force is equally untenable for states whose security and prosperity depend on rules that apply to everyone. 

“What do we do as a middle power now?” he asked.  The question, in his framing, is not rhetorical.  It is the central strategic challenge facing a significant portion of the international community, and it does not yet have an answer.  What it demands is the construction of a third path, one that does not yet exist but that middle powers may have both the incentive and the collective capacity to build.

Ambassador Julian Braithwaite, former British Ambassador to the WTO, UN, and Other International Organizations in Geneva. 

Ambassador Braithwaite offered a candid counterweight to the more aspirational threads of the discussion.  The history of international order, he argued, has never been one of genuinely collective governance.  It has always been shaped by the interests and the power of the states willing and able to enforce its rules.  That is a structural observation and it carries direct implications for what middle powers can realistically hope to achieve. 

The Russian position, he noted, has been about a world organized around spheres of influence, where great powers exercise predominant authority within their respective regions and smaller states navigate their relationships with those powers accordingly.  That model has deep historical roots, predating the post-1945 order and never fully displaced by it.  The current US posture, in Ambassador Braithwaite’s reading, reflects a degree of comfort with that framework, a willingness to think about international relations in terms of deals, bilateral leverage, and zones of interest rather than universal rules and multilateral institutions.  China, meanwhile, has been watching the erosion of the rules-based order with considerable strategic interest.  A world in which the rules-based order weakens is not, from China’s perspective, an unambiguously unwelcome development.  The space that opens as multilateral institutions atrophy is one in which bilateral leverage, economic coercion, and regional dominance become more consequential. 

For middle powers, the challenge is that none of these trajectories leave an obvious role.  A world organized around great power spheres of influence is precisely the world in which states that are too large to be ignored but too small to set the terms find themselves most exposed.  “We need to be realistic,” he said, “about what rules-based order can be constructed on top of the ashes of this one.”  The aspiration to build something better is necessary.  But aspiration without a clear account of who will build it, on what foundation, and with what enforcement capacity is not architecture; it is hope.

Jason Steinbaum, Former Staff Director, Committee on Foreign Affairs, US House of Representatives

Steinbaum offered a perspective that resisted the session’s more pessimistic conclusions without dismissing them.  “We may not be at a complete rupture,” he said, “but we can discern some things from the current actions.  There is still a thirst for a rules-based order, for democracy, although it’s not in all corners.” 

Steinbaum pointed to a debate that he argues is still very much alive within the US itself.  The war powers framework, which governs the constitutional relationship between the executive branch and Congress over the use of military force abroad, has been stretched and strained repeatedly since its codification in the War Powers Resolution of 1973.  Presidents of both parties have pushed its limits; Congress has oscillated between reasserting its authority and acquiescing to executive action.  That tension is not resolved, and the question of who in the US constitutional system has the authority to commit the country to military action, and under what conditions, remains genuinely contested.  His broader point was that the internal US debate about the country’s role in the world and the limits of executive power is unfinished.  The outcome of that debate will have consequences that extend well beyond US borders, which is precisely why the international legal community has a stake in following it closely.

Conclusion

The urgency in this post’s contributions suggests that these are not merely academic questions. Dr. Crane states it plainly: “We are in an age of aggression, a corollary of the rise of the strongman, where the unilateral use of force outside the UN paradigm is becoming a norm.”  The question then becomes whether we can live in a world where the UN does not matter.

The experts converge not on pessimism, but on a specific and actionable form of urgency.  The rupture is real.  The normative vocabulary is losing value. The institutions are atrophying.  The middle powers face a choice between constructing an alternative architecture and acquiescing to a world ordered by spheres of influence.

But acquiescence, as Ambassador Whyte-Gomez reminds us, is a choice too, and it is the choice that will determine whether what has been broken can eventually be rebuilt.  The working group’s consensus is that it cannot afford to be made by default.  At historical inflection points, lawyers and practitioners can stop, think, and help construct the vocabulary for what comes next.