Table of Contents

1. Introduction
2. From Copenhagen to Transformation: The Formation of Conditionality in the Eastern Enlargement Process
3. Conditionality under Strain: The Western Balkans and the changing context of enlargement
4. Reconfiguring Conditionality: Between sectoral integration and geopolitical enlargement
5. Conclusion

A. Introduction

Enlargement has long been one of the European Union’s central instruments for defining the continent’s political and geographical contours. From early en­large­ments primarily aimed at consolidating and expanding a common market, to later rounds driven by explicitly political objectives, en­large­ment has served both economic and normative purposes. While the accessions of 1973 and 1995 were oriented mainly towards market integration and economic cohesion, the Southern and Eastern en­large­ments since the 1980s increasingly framed accession as a tool for making Europe safe for democracy. En­large­ment thus became a strategy for fostering the societal foundations of democratic stability – economic development, elite commitment to democratic rules, and the in­sti­tu­tional infrastructure required for democratic gov­er­nance. In this understanding, en­large­ment served to anchor Europe in a shared commitment to liberal democracy and open markets, thereby transforming the continent into a space of stability, security, and peace, while simultaneously enabling the Union to project these achievements beyond its borders.

While democracy and market economy had always figured prominently in the logic of EU en­large­ment, con­di­tion­al­ity acquired a qualitatively new role with the end of the Cold War and the accession aspirations of former communist states. En­large­ment was no longer merely a process of incorporation into an existing political and economic order but simultaneously became a project of profound domestic transformation. It was under these circumstances that EU con­di­tion­al­ity emerged as the central mechanism linking the promise of integration to demonstrable progress in political, economic, and in­sti­tu­tional reform, allowing the EU to steer domestic change in candidate countries. This logic found its most explicit expression in the EU’s Copenhagen criteria, which codified accession requirements and provided a more systematic and comparable framework for assessing candidates’ readiness for membership.

In the en­large­ment rounds of 2004 and 2007, this model of con­di­tion­al­ity appeared to prove remarkably successful. The prospect of EU membership, credibly linked to clearly defined reform benchmarks, coincided with sustained economic growth and processes of democratic consolidation in acceding states. For a time, en­large­ment seemed to confirm the trans­for­ma­tive power of con­di­tion­al­ity. Nevertheless, in the years that followed, signs of strain began to emerge. Patterns of democratic backsliding in several states post-accession have raised questions about the sustainability of the trans­for­ma­tions induced under con­di­tion­al­ity. At the same time, the protracted and increasingly complex en­large­ment processes in the Western Balkans have cast doubt on the effectiveness of con­di­tion­al­ity in contexts char­ac­terised by diminishing credibility, new external pressures and heightened geopolitical and illiberal contestation.

This paper examines the evolving understanding of con­di­tion­al­ity in EU en­large­ment. It begins with a retrospective reflection on the en­large­ment rounds of 2004 and 2007 and the trans­for­ma­tions they set in motion, tracing how the abstract Copenhagen criteria were translated into concrete processes of Europeanisation with an evolving legal framework char­ac­terised by a distinctive interplay between legal rules, political discretion, and fiscally mediated, incentive-based con­di­tion­al­ity. Because of its success, this con­di­tion­al­ity-driven gov­er­nance expanded beyond accession itself, shaping policy instruments such as the European Neighbourhood Policy. Con­di­tion­al­ity here is un­der­stood not as a hierarchical legal relationship or a form of coercion, but as a gov­er­nance arrangement in which com­pli­ance is generated through incentives – most notably access to funds, participation in in­sti­tu­tional fora, and the prospect of membership.^[1]A. Baraggia, M. Bonelli, Linking Money to Values: The New Rule of Law Con­di­tion­al­ity Regulation and Its Constitutional Challenges, German Law Journal 23 2022, pp. 131 et seq. Building on this conceptualisation, the paper then turns to contemporary en­large­ment processes to assess how con­di­tion­al­ity has changed since the “Big Bang” en­large­ment, examining shifts in both requirements and incentives, and situating these developments within a broader set of challenges facing merit-based and con­di­tion­al­ity-driven en­large­ment.

B. From Copenhagen to Transformation: The Formation of Conditionality in the Eastern Enlargement Process

The EU’s groundbreaking eastward en­large­ment in May 2004 fundamentally shaped the Union’s subsequent development. The decision to proceed with en­large­ment in a ‘Big Bang’ format resulted in the accession of the Czech Republic, Cyprus, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia, marking the most extensive territorial and political expansion in the EU’s history. Despite substantial criticism and evident shortcomings, the policy-driven en­large­ment ne­go­tia­tions since the late 1990s have provided significant impetus for the consolidation of democratic institutions, market reforms, and the rule of law across new Member States. From the perspective of the accession countries, “becoming EU member states was ultimately seen as a confirmation of their place as part of democratic and prosperous Europe from which they were torn by the Communist regimes”.^[2]M. Mišík, M. Brusenbauch Meislová, 20th Anniversary of the EU Eastern En­large­ment: Stocktaking of the Membership Experience, Challenges, and Opportunities, Journal of Contemporary … Continue reading Notwithstanding economic weaknesses and ongoing disputes over the future of the EU’s constitutional architecture, parliamentary decisions in the EU Member States as well as referendums and parliamentary approvals in the candidate countries demonstrated solid legitimacy on both sides, despite limited public enthusiasm in the old Member States.^[3]B. Lippert, Die Erweiterungspolitik der Europäischen Union, in: Weidenfeld/Wessels (Hrsg.), Jahrbuch der Europäischen Union 2003/2004, 2004, pp. 419-30. This unprecedented en­large­ment un­folded under conditions of pronounced political urgency and is best un­der­stood as a policy char­ac­terised by procedural pragmatism. It re­tro­spec­tively appears to have been a fast-track process, based on newly established policies and in­sti­tu­tional arrangements on the EU side and accompanied by extensive economic, administrative, and political support for the candidate countries.^[4]H. Grabbe, Six Lessons of En­large­ment Ten Years On: The EU’s Trans­for­ma­tive Power in Retrospect and Prospect, JCMS: Journal of Common Market Studies 52 2014, p. 40. Rather than following a com­pre­hen­sive functional master plan or a clearly articulated normative blueprint, en­large­ment gov­er­nance evolved in­cre­men­tally. Gradual policy developments, subsequent adjustments, and political realignments shaped the instruments the European Commission employed throughout the preparation and negotiation phase. As Anghel and Jones observe, this pragmatism extended beyond the Commission to the European Council and national governments: “The principal actors in the European Union did not plan where they ended up in the en­large­ment story; rather, they made the best of a challenging set of influences and events”.^[5]V. Anghel, E. Jones, Failing Forward in Eastern En­large­ment: Problem Solving through Problem Making, Journal of European Public Policy 29 2022, p. 1106. The democratic backsliding after accession in Hungary, and to a more limited and temporally contained extent, in Poland also showed the fragility of the normative adjustments.

This mixture of normative framings – centred on democracy, the rule of law, and market-economy standards – and pragmatic, problem-solving-oriented control mechanisms has increasingly been interpreted as a specific method of European unification. En­large­ment combined rational-in­sti­tu­tionalist motives aimed at stabilising the continent and enhancing the competitiveness of the European market under global pressure, with constructivist self-descriptions of the EU as “normative power”, while deliberately preserving room for political discretion. Internally, the Union did not pursue a single com­pre­hen­sive constitutional reform prior to en­large­ment. Instead, it relied on incremental treaty-based adjustments, notably the Amsterdam and Nice Treaties, reflecting a pragmatic approach to the simultaneous challenges of deepening and widening with functionality outweighing in­sti­tu­tional elegance. Reform steps were often undertaken only once blockages became apparent, further underlining the tentative and adaptive character of en­large­ment gov­er­nance. From today’s perspective, marked by re-autocratisation trends and the decay of the rule-based global order, the en­large­ment policy of the 1990s and early 2000s appears to have been shaped by an illusory end-of-history paradigm,^[6]F. Fukuyama, The End of History, The National Interest 16 1989, pp. 3–18. assuming the fundamental attractiveness and self-sustaining superiority of democratic gov­er­nance and market economies once in­sti­tu­tional alignment had been achieved.

This procedural pragmatism must be situated within the broader trans­for­ma­tion of EU en­large­ment following the Cold War. The EU faced a challenge it had not previously encountered at this scale: how to organise en­large­ment toward a large group of politically and economically transforming states under conditions of in­sti­tu­tional uncertainty, asymmetric readiness, and high geopolitical stakes. The prospect of accession for post-communist states created both strategic opportunities and regulatory risks. The Union responded by constructing an increasingly structured en­large­ment regime designed to discipline, sequence and incentivise domestic trans­for­ma­tion and based on con­di­tion­al­ity that translated broad accession principles into monitorable and incentive-linked reform requirements. What is now Article 49 TEU contains only sparse admissibility criteria; the practical gov­er­nance of en­large­ment was therefore constructed through in­sti­tu­tional practice: European Council criteria-setting, Commission opinions, screening pro­ce­dures and negotiation frameworks. En­large­ment thus developed less as a codified regime than as an evolving in­sti­tu­tional process combining political discretion with structured com­pli­ance assessment.^[7]O. Costa, G. Marti, K. Caunes, A Roadmap for Enlarging and Reforming the European Union: Taking the Report of the “Group of Twelve” Seriously, European Law Journal 30 2024, p. 468; A. Duff, … Continue reading The Copenhagen criteria, adopted in 1993 and reaffirmed in Madrid in 1995,^[8]M. Fröhlich, A. Trautmann, 25 Jahre europäischer Beitrittsprozess von Osterweiterung über Stillstand zu notwendigen Reformen, Zeitschrift für europarechtliche Studien 25 2022, pp. 733–54. functioned as normative anchors within this architecture. However, they were permanently embedded in a decision structure in which the final determination remained political.^[9]R. Coman, A. Buzogány, The European Union’s Response to the Rule of Law Crisis and the Making of the New Con­di­tion­al­ity Regime, JCMS: Journal of Common Market Studies 62 2024, … Continue reading This legal underdetermination proved constitutive rather than accidental. Because the Treaties did not predefine an accession methodology, the Union could progressively translate abstract accession norms into operational benchmarks and reform requirements.

The Copenhagen criteria are conventionally divided into three areas: political criteria relating to the stability of institutions guaranteeing democracy, the rule of law, human rights, and respect for and protection of minorities; an economic criterion requiring a functioning market economy capable of withstanding competitive pressures within the internal market; and the adoption of the acquis communautaire.^[10]T. Marktler, The Power of the Copenhagen Criteria, Croatian Yearbook of European Law and Policy 2 2008, pp. 343–64. Yet both the political and economic criteria remained deliberately vague. EU heads of state and government avoided agreeing on explicit definitions of democracy, adequate rule-of-law standards, or human rights obligations, not least because these concepts were themselves only partially codified at EU level until the Lisbon Treaty entered into force in 2009. From a constructivist perspective, such vagueness poses clear risks. Com­pli­ance with international norms typically requires clarity and specificity; the more general the benchmarks, the greater the likelihood that they will be ignored, selectively interpreted, or contested. At the same time, the inclusion of vague terms may constitute a strategic choice, facilitating flexible negotiation and compromise under conditions of heterogeneity and uncertainty.^[11]M. Finnemore, K. Sikkink, International Norm Dynamics and Political Change, International Organization 52 1998, pp. 887–917; T. Linsenmaier, D. Schmidt, K. Spandler, On the Meaning(s) of Norms: … Continue reading Such an impact has been, for example, particularly visible in the political criterion of respect for and protection of minorities.^[12]G. Sasse, The Politics of EU Con­di­tion­al­ity: The Norm of Minority Protection during and beyond EU Accession, Journal of European Public Policy 15 2008, pp. 842–60. The obligations reflected concerns among EU leaders that violent conflicts, minority disputes or severe discrimination might be imported into an enlarged Union. However, during the Eastern en­large­ment, the EU itself had not yet developed com­pre­hen­sive internal standards in this field. As a result, the European Commission relied heavily on norms borrowed from other regional or­gani­sa­tions, most notably the Council of Europe’s Framework Convention for the Protection of National Minorities. Applying externally developed norms within the EU’s con­di­tion­al­ity framework generated legitimacy problems, as several Member States had not ratified the Convention themselves while demanding com­pli­ance from accession countries, which created a clear normative double standard. Minority protection has been absent from association agreements prior to the Copenhagen criteria, after which more concrete obligations have been imposed on the candidate countries, particularly in the Baltic cases, with an emphasis on language protection. Across Eastern candidates, the EU Commission reports increasingly focused on Roma protection, though these demands were softened toward the end of ne­go­tia­tions, suggesting strategic relaxation. Overall, minority-related con­di­tion­al­ity expanded over time but remained unevenly applied.

All in all, the con­di­tion­al­ity regime established for Eastern en­large­ment was the most com­pre­hen­sive in the EU’s history.^[13]H. Grabbe, European Union Con­di­tion­al­ity and the “Acquis Communautaire”, International Political Science Review / Revue Internationale de Science Politique 23 2002, … Continue reading Scholarly accounts of its impact have focused either on strategic calculations (where domestic actors adopt EU rules to solve policy problems or secure material benefits) or on processes of socialisation and norm internalisation.^[14]R. A. Epstein, U. Sedelmeier, Beyond Con­di­tion­al­ity: International Institutions in Post­com­mu­nist Europe after En­large­ment, Journal of European Public … Continue reading However, even during the first East­ern en­large­ment, it was a misperception to assume that the EU operated as a monolithic entity applying a uniform set of conditions independently of context.^[15]D. Kochenov, EU En­large­ment and the Failure of Con­di­tion­al­ity: Pre-Accession Con­di­tion­al­ity in the Fields of Democracy and the Rule of Law, Kluwer … Continue reading The EU’s self-portrayal of ‘objective’ and equal treatment across candidates masked the central role of political compromise and steering in determining whether and how standards were deemed satisfied.^[16]J. Hughes, G. Sasse, C. Gordon, Con­di­tion­al­ity and Com­pli­ance in the EU’s Eastward En­large­ment: Regional Policy and the Reform of Sub-National Government, … Continue reading The Eastern en­large­ment can therefore be un­der­stood as an iterative negotiation process in which the Commission and Member States repeatedly defined interim targets, in­tro­duced transitional periods, and established sectoral exceptions, such as in labour mobility or agricultural subsidies, to avoid political deadlock.

Within this architecture, con­di­tion­al­ity operated through structural asym­me­try. Candidate states were subjected to dense com­pli­ance ex­pec­ta­tions, while accession outcomes remained politically contingent. Fulfilling benchmarks never generated a legal entitlement to membership. In the con­text of the Eastern en­large­ment 2004, strategic calculations, geopolitical considerations, but also normative commitments of Member States constituted the decisive variables shaping accession decisions. Subsequent assessments have stressed the gains derived from the Eastern expansion of the Union,^[17]Mišík/Brusenbauch Meislová (Fn. 3); P. Pasimeni, Twenty Years After the Big En­large­ment: Integration Within the Single Market, Intereconomics 59 2024, pp. 222–3. yet also note that successive crisis cycles, geopolitical shocks and widening preference divergence among Member States have made the sustainability of earlier integration trajectories increasingly fragile – a development that directly affects the credibility and operation of en­large­ment con­di­tion­al­ity,^[18]Anghel/Jones, (Fn. 6); P. Bargués u.a., Engagement against All Odds? Navigating Member States’ Contestation of EU Policy on Kosovo, The International Spectator 59 2024, pp. 19–38. fore­shad­ow­ing the challenges that would later become fully visible in the Western Balkans and beyond.

C. Conditionality under Strain: The Western Balkans and the changing context of enlargement

Rather than representing a structural shift away from a previously coherent con­di­tion­al­ity regime, the Western Balkans en­large­ment process makes weaknesses of con­di­tion­al­ity even more visible. Critical legal scholarship has long described it as a politically malleable and often overestimated gov­er­nance device, marked by shifting benchmarks, limited legal determinacy and selective application, particularly in the non-acquis fields of democracy and rule of law.^[19]D. Kochenov, Overestimating Con­di­tion­al­ity, SSRN, 5.1.2014, <https://papers.ssrn.com/abstract=2374924>. While the Copenhagen framework and chapter-based ne­go­tia­tions formally remained intact, their operation has been transformed by four cumulative pressures: protracted accession timelines, declining membership credibility, crisis-driven geopolitical reprioritisation, and the migration of internal EU rule-of-law and budgetary control instruments into the en­large­ment sphere. The functionality of con­di­tion­al­ity has been recalibrated: rather than primarily serving as a vehicle for com­pre­hen­sive domestic trans­for­ma­tion, it was increasingly geared to risk containment and stability management, with corresponding implications for both effectiveness and normative credibility.

Western Balkan en­large­ment has been char­ac­terised by extended stagnation, repeated procedural resets and shifting methodologies. A growing body of scholarship highlights that the credibility of the membership perspective has eroded, weakening the incentive logic that con­di­tion­al­ity presupposes.^[20]M. G. Amadio Viceré, M. Bonomi, External Differentiation as a Strategy of System Main­te­nance: EU En­large­ment towards the Western Balkans, West European Politics 2025, … Continue reading When reform efforts no longer yield predictable forward movement, con­di­tion­al­ity risks becoming symbolically demanding but strategically blunt. Empirical assessments of rule-of-law promotion in the region reinforce this diagnosis. The EU Court of Auditors’ (ECA) evaluation concludes that EU action in the Western Balkans contributed to formal reforms, but outcomes remain “technical and operational”. The delivery of training courses, the provision of experts to help draft legislation or guidelines, or the renovation of court buildings (as some examples of EU assistance provided) contributed to efficiency, but without the political will in the candidate countries, the ECA concluded, EU conditions and financial means had only limited impact.^[21]European Court of Auditors, EU support for the rule of law in the Western Balkans: despite efforts, fundamental problems persist, Special Report 01/2022 (Luxembourg: European Court of Auditors, … Continue reading This gap between formal com­pli­ance and substantive trans­for­ma­tion recurs across studies relating in particular to the highly sensitive rule of law and democracy related en­large­ment negotiation chapters, which frequently report in­sti­tu­tional redesign without durable behavioural change.^[22]Rabinovych, (Fn. 21), p. 720. Compared to the 2004/2007 Eastern en­large­ment con­di­tion­al­ity has thus become more detailed but not necessarily more effective – a typical case of increasing monitoring den­sity paired with declining trans­for­ma­tive return. The 2020 “new method­ol­ogy” for en­large­ment – after all seven years after the last en­large­ment with Croatia joining in 2013 – intensified this trend rather than mitigating it. By clustering chapters and placing the “fundamentals” (especially Chapters 23 and 24 on judiciary, fundamental rights and justice and home affairs) at the centre of negotiating se­quenc­ing, the Commission sought to restore procedural struc­ture and political credibility after the French veto on opening accession ne­go­tia­tions with Albania and North Macedonia in 2019. The reform of the en­large­ment methodology was directly shaped by the French non-paper, which argued that trans­for­ma­tion in candidate states had been “too slow” and that tangible benefits for citizens remained insufficient, calling instead for more stringent conditions, stage-based integration and a formally reversible process.^[23]France, Non-Paper: Reforming the European Union Accession Process, November 2019, <https://www.politico.eu/wp-content/uploads/2019/11/Enlargement-nonpaper.pdf> (accessed 17.11.2025). The 2020 Communication of the European Commission reframes con­di­tion­al­ity from a primarily forward-driving trans­for­ma­tion mechanism into a tightly managed com­pli­ance regime centred on the fundamentals cluster and continuous political steering. The resulting model preserves con­di­tion­al­ity but strengthens the weight of sanction capacities, reversibility and executive oversight, recalibrating con­di­tion­al­ity from a rewards structure for reform success toward an ongoing risk-control architecture.^[24]European Commission, Enhancing the accession process – A credible EU perspective for the Western Balkans, COM(2020) 57 final, … Continue reading The in­tro­duc­tion of new instruments, such as the Interim Benchmark Assessment Report (IBAR), illustrates this move toward granular com­pli­ance tracking. It carries particular weight in the accession process as it assesses whether interim benchmarks in Chapters 23 and 24 have been met, on which progress across all other reform and negotiation areas depends. Still, the robustness of this seemingly technical assessment process is questioned, as IBAR approvals may signal political encouragement rather than fully verified reform performance.^[25]M. Muharemović, P. Usvatov, IBAR: Der Zwischenbericht zur Rechtsstaatlichkeit im EU-Beitrittsprozess, Konrad-Adenauer-Stiftung, Länderberichte, 2024, … Continue reading Montenegro was the first of the Western Balkan countries to receive a positive IBAR in mid-2024, thereby opening the door to the provisional closure of other negotiating chapters.^[26]European External Action Service (EEAS), Historic Day: Montenegro receives positive IBAR, Delegation of the EU to Montenegro, Press and Information Team, 27.06.2024, … Continue reading However, the 2025 en­large­ment report indicates that while key legislative reforms have been adopted on paper, enforcement and in­sti­tu­tional practice continue to lag behind.^[27]Commission Staff Working Document, Montenegro 2025 Report, SWD(2025) 754 final/2, 4.11.2025, … Continue reading This points to a core tension of con­di­tion­al­ity: benchmark fulfilment can enable procedural advancement even where deeper gov­er­nance deficits remain unresolved, creating a partial decoupling between formal performance indicators and substantive progress. Serbia shows a related pattern under different conditions. Having accepted the revised methodology in 2021, it remains formally bound to intensified rule-of-law scrutiny, yet ne­go­tia­tions have stagnated in key clusters amid persistent corruption and gov­er­nance concerns. Despite documented de­mo­cra­tic and rule-of-law backsliding, Serbia has continued to receive procedural advancement signals where technical conditions were met, in­di­cat­ing that economic and geopolitical considerations may override a strictly merit-based fundamentals approach.^[28]M. Emerson, S. Blockmans, A Redynamised EU En­large­ment Process, but Hovering between Accession and the Alternatives, SCEEUS Report No 1 2025, Stockholm Centre for Eastern European Studies, … Continue reading Serbia’s growing importance for the EU’s lithium and critical raw materials strategy increases the political stakes of confrontation, creating additional incentives for restraint in the activation of negative con­di­tion­al­ity instruments.^[29]S. Subotic, Serbia’s Lithium Dilemma_ A Challenging Test for the EU’s Raw Materials Diplomacy, Future Europe, 20.9. 2025, … Continue reading This illustrates how strategic sectoral interests can moderate the practical deployment of negative con­di­tion­al­ity.

While the Serbian case illustrates that the strengthened enforcement vocabulary of the revised methodology does not necessarily translate into the systematic activation of reversibility, the North Macedonian trajectory highlights a different vulnerability of the same framework: even where Commission assessments are broadly positive and technical criteria appear fulfilled, progress may be blocked or redirected through member state-driven conditions and the politically elastic notion of “good-neighbourly relations”. In practice, bilateral disputes, notably Greece’s long-standing veto linked to the Macedonian state name issue and Bulgaria’s subsequent objections concerning historical interpretation, language and minority recognition, halted the pro­gres­sion of negotiation stages and contributed to domestic perceptions of inconsistency in the application of the Union’s merit-based approach.^[30]B. Altiparmakova- Marusic, Mickoski: Instead of the Balkans Being Europeanized, Europe is Balkanized; Macedonia Has to Have EU Path Predictability, MIA, 16.2.2025, … Continue reading Through the combination of unanimity in decision-making and the loosely defined principle of “good neighbourliness” as an additional benchmark, EU Member States have transformed what was intended as a norm of mutual respect into a strategic instrument for advancing national interests. Under such conditions, con­di­tion­al­ity generates political backlash dynamics in candidate states, including heightened nationalist rhetoric and populist mobilisation,^[31]A. Zdeb, Fragility of Post-Conflict Consociational Democracies: Bosnia and Herzegovina and North Macedonia in the Quest for Democratic Stability, in Sawicka/Gruszczak/Zdeb, Democracy and Its … Continue reading which complicate rather than reinforce the reform and stabilisation goals associated with EU con­di­tion­al­ity.

Taken together, these developments distinguish Western Balkan con­di­tion­al­ity from the former “Big Bang” Eastern en­large­ment model along three structural dimensions: reduced credibility of the membership perspective, increased political mediation and fragmentation of instruments, and a reordered objective hierarchy in which stability and geopolitical alignment carry greater operational weight relative to trans­for­ma­tive depth. The EU’s con­di­tion­al­ity has been reconfigured towards the Western Balkans: it operates through more granular monitoring, expanded com­pli­ance instruments and reversible se­quenc­ing, while simultaneously becoming more exposed to political gatekeeping and cross-sectoral linkage. This densification does not nec­es­sar­ily strengthen enforcement capacity. It also widens dis­cre­tionary margins in both activation and suspension, loosens the coupling between benchmark fulfilment and procedural advancement, and increases the scope for member state-driven and geopolitical filtering. The Western Balkans experience, therefore, suggests that intensified con­di­tion­al­ity does not automatically produce stronger trans­for­ma­tive effects; under conditions of weakened credibility and politicised application, it may instead yield diminishing reform returns and greater contestation of its legitimacy.

D. Reconfiguring Con­di­tion­al­ity: Between sectoral integration and geopolitical enlargement

Recent developments in the Union’s en­large­ment policy suggest not only mounting pressure on existing con­di­tion­al­ity frameworks, but a change in how en­large­ment itself is functionally deployed as a gov­er­nance instrument. The en­large­ment turn triggered by Russia’s war against Ukraine does not merely intensify existing pressures on con­di­tion­al­ity but alters its functional role. With the rapid granting of candidate status to Ukraine and Moldova, the Union has begun to use the en­large­ment framework not only as a trans­for­ma­tion instrument, but also as a vehicle for strategic an­chor­ing, accelerated align­ment and sectoral incorporation under conditions of geopolitical urgency.^[32]A. Gawrich, D. Wydra, Perspektiven der Erweiterung – Ein Versprechen, Multiple Szenarien, Integration 46 2023, pp. 229–43. En­large­ment gov­er­nance is thereby partially detached from its traditional se­quenc­ing logic and increasingly organised around differentiated access formats, staged integration and policy-specific participation. The current reconfiguration of en­large­ment con­di­tion­al­ity cannot be adequately captured by an incremental extension of existing typologies. Rather than a mere accumulation of instruments, it reflects a qualitative shift in how con­di­tion­al­ity operates as a mode of gov­er­nance. Con­di­tion­al­ity increasingly operates less as a linear incentive for com­pre­hen­sive political trans­for­ma­tion, but more as a re­la­tional gov­er­nance device structuring differentiated access, allocating risk, and stabilising cooperation under uncertainty.^[33]K. Slootmaeckers, A Relational Approach to Study Europeanisation via En­large­ment, Geopolitics 2025, p. 1–27. This shift foregrounds a con­sti­tu­tional paradox of en­large­ment law: con­di­tion­al­ity performs extensive regulatory and steering functions despite lacking a Treaty-based legal framework, while the absence of any enforceable right to accession leaves com­pli­ance outcomes ultimately contingent on Member State discretion.^[34]Kochenov/Basheska (Fn. 8), p. 5. Con­di­tion­al­ity should therefore be read less as a stable doctrinal template than as an instrument whose operative meaning shifts with changing en­large­ment priorities, particularly when en­large­ment is mobilised as a geostrategic foreign-policy instrument in response to external shocks.^[35]M. Ghincea, L. Pleșca, From Transformation to Demarcation: Explaining the EU’s Shifting Motivations of the En­large­ment Policy, Journal of European Public Policy 32 2025, … Continue reading Candidate status and the opening of ne­go­tia­tions are weak predictors of actual accession trajectories, since they primarily activate pro­ce­dures of review and negotiation without constraining the Union’s discretion over the pace, direction, or outcome of accession.^[36]F. Schimmelfennig, The Advent of Geopolitical En­large­ment and Its Credibility Dilemma, in Džankić/Kacarska/Keil (eds.), A Year Later, War in Ukraine and Western Balkan (Geo)Politics, … Continue reading What matters is less formal com­pli­ance with predefined benchmarks than how integration-related tensions are managed and redistributed across policy domains and in­sti­tu­tional arenas.^[37]Slootmaeckers (Fn. 34). The Western Balkans experience had already captured this logic: political assurances of membership were formally reiterated (e.g. at the Sofia summit 2018), while the 2020 reform of en­large­ment methodology increased Council control, reversibility and geopolitical discretion, allowing accession steps to be suspended or delayed despite benchmark fulfilment, further eroding the expectation-stabilising function of con­di­tion­al­ity.^[38]M. Petrovic, N. Tzifakis, A Geopolitical Turn to EU En­large­ment, or Another Postponement? An Introduction, Journal of Contemporary European Studies 29 2021, pp. 157–68. But it also resonates with the post-2022 cycle: initial crisis leadership by the Commission enabled rapid agenda-setting, but these innovations were only partially in­sti­tu­tionalised (by attaching reform benchmarks to funding disbursement rather than to accession progression); the centre of gravity then shifted towards Council politics, ad hoc coalitions, and veto players operating under unanimity.^[39]Koval/Vachudova, (Fn. 36).

While formally anchored in accession benchmarks and Copenhagen-based criteria, con­di­tion­al­ity is increasingly operationalised across adjacent regimes – an evolution traced by Rabinovych and Pintsch (2025) in their analysis of the Union’s wartime con­di­tion­al­ity toolbox vis-à-vis Ukraine. They conceptualise this toolbox as comprising three functionally distinct yet partially overlapping con­di­tion­al­ity regimes. Pre-accession con­di­tion­al­ity is organised around the seven conditions attached to Ukraine’s candidate status, remaining embedded in the broader accession logic of continuous, stage-specific con­di­tion­al­ity, theoretically governing the progression of accession ne­go­tia­tions (if the veto of member states can be overcome), most prominently with regard to the permanent fulfilment of rule-of-law standards. Here, con­di­tion­al­ity operates primarily as an orientation and signalling instrument structuring long-term reform trajectories and societal mobilisation. Macro-financial (MFA) con­di­tion­al­ity, by contrast, is defined by legally specified, time-bound gov­er­nance and rule-of-law requirements that are directly tied to disbursement decisions, reflecting a predominantly intergovernmental bargaining logic with limited space for local ownership. Recovery-related con­di­tion­al­ity, in­sti­tu­tionalised through the Ukraine Facility, embeds reform priorities within a multiannual reconstruction and resilience framework, combining elements of ex-ante and ex-post con­di­tion­al­ity while an­chor­ing them in programme-based funding and implementing structures. Rabinovych and Pintsch demonstrate that these regimes in­sti­tu­tionalise a systematic coupling of en­large­ment con­di­tion­al­ity with the EU’s Global-Strategy-based crisis management and resilience agenda, thereby reconfiguring con­di­tion­al­ity from an accession-sequenced com­pli­ance device into a hybrid mode of gov­er­nance situated at the intersection of en­large­ment law and conflict management, hinting towards an increasingly differentiated and pragmatic engagement with accession candidates. This logic is also exemplified by the expansion of external differentiated co­op­era­tion: a form of consensus-based, non-homogeneous and partly ad hoc participation through which accession candidates are se­lec­tively integrated into EU policy responses short of membership. Operating largely in­de­pen­dently of accession se­quenc­ing and con­di­tion­al­ity in the strict sense, this mode of engagement reflects a pragmatic recalibration of participation boundaries in response to crisis-induced interdependence.^[40]Amadio Viceré/Bonomi, (Fn. 21). Western Balkan countries are embedded in operational cooperation with Frontex, Europol, Eurojust and EUAA (European Union Agency for Asylum), enabling joint operations, data exchange and functional alignment in migration, border management and criminal justice without membership. While this par­tici­pa­tion remains formally non-decisional and differentiated across agencies – being most advanced in Frontex, more structured but constrained in Europol, and largely capacity-building-oriented in EUAA – it nonetheless places Western Balkan authorities in routine, quasi-internal operational roles within core EU policy domains.^[41]I. Damjanovski, Z. Nechev, External Differentiated Integration in Justice and Home Affairs: Participation of the Western Balkan Countries in EU Agencies, EU-IDEA Policy Paper No. 20 2022, … Continue reading This differentiated par­tici­pa­tion is legally structured through agency-specific eligibility regimes: Frontex deployments rest on status agreements and operational plans embedding fundamental-rights safeguards and suspension clauses; Europol and Eurojust cooperation is calibrated through the law of information exchange, with operational depth contingent on the legality of (personal) data transfers; and EUAA external action proceeds via Commission-approved working arrangements subject to human-rights screening. Ukraine has followed a comparable but markedly accelerated trajectory since 2022, char­ac­terised by intensified cooperation with Europol^[42]Agreement between Ukraine and the European Police Office on Operational and Strategic Cooperation, concluded at The Hague on 14 December 2016, entered into force 2017, … Continue reading and Eurojust,^[43]The Cooperation Agreements were signed in June 2016 and are operational since August 2018. As early as 2022, Eurojust supported the establishment of a Joint Investigation Team to investigate alleged … Continue reading and cooperation between Frontex and the European Advisory Mission to Ukraine (EUAM),^[44]In February 2024, Frontex and the EUAM Ukraine signed a working arrangement to cooperate in combatting cross-border crime and dealing with irregular migration at the EU’s Eastern borders, see: … Continue reading and full operational in­te­gra­tion into the EU Civil Protection Mechanism.

In this setting, gradual integration becomes a concrete modality for translating con­di­tion­al­ity into actionable gov­er­nance: major funding instruments embed reform benchmarks, timelines, and sector-specific “phasing-in” arrange­ments.^[45]P. Buras u.a., Gradual Integration: Bringing Aspiring Members Closer to the EU, European Council on Foreign Relations, 2025, … Continue reading Sectoral integration decouples functional par­tici­pa­tion from the formal se­quenc­ing of accession chapters, enabling selective access to internal market segments, energy, digital, or justice and home affairs policies on the basis of capacity and alignment rather than com­pre­hen­sive com­pli­ance. This functional rationalisation, however, does not depoliticise en­large­ment gov­er­nance. On the contrary, formalisation relocates political contestation into distributive arenas in which access to funds, programmes and sectoral par­tici­pa­tion remains subject to member-state gatekeeping and unanimity-sensitive decision-making. As intermediate stages become increasingly benefit-rich, con­di­tion­al­ity is no longer exhausted by com­pli­ance assessment but turns on distributive judgments over who gains access on what terms, and with what tolerance for backsliding – particularly where crises compress asymmetries of dependence and enhance candidate bargaining power.^[46]Amadio Viceré/Bonomi, (Fn. 21), p. 1167. It is precisely this relocation of con­di­tion­al­ity into distributive decision-making that strains collective steering capacities. The post-2022 phase illustrates how, even as en­large­ment is rhetorically elevated to a strategic imperative, gov­er­nance increasingly unfolds through leaderless intergovernmental bargaining and bilateral veto practices that undermine the predictability and en­force­abil­ity of con­di­tion­al­ity.^[47]Koval/Vachudova, (Fn. 36). This constellation marks the point at which geopolitics intersects with constitutional structure: geopolitical urgency can erode the normative legitimacy of bilateral gatekeeping, insofar as rhetorical com­mit­ments to en­large­ment continue to constrain most Member States (except for those who like Hungary no longer internalise the Union’s value framework);^[48]D. Leuffen u.a., Rhetorical Action in a Liberal International Order in Crisis: Theorising EU and NATO En­large­ments Post-2022, Journal of European Public Policy 32 2025, pp. 3113–58. yet it simultaneously risks diluting the enforceability of the “fundamentals” when integration advances through functional inclusion rather than accession se­quenc­ing. Keil sharpens this tension: a re-foundation of en­large­ment primarily on geopolitical interest-selection would require specifying “Union interests” as operative admission and se­quenc­ing criteria, shifting the justificatory basis of en­large­ment away from a normative thick legal-con­sti­tu­tional project toward a thinner security-economy rationale – an adjustment that would reverberate back onto intra-Union rule-of-law discipline and the credibility of values-based contestation.^[49]S. Keil, En­large­ment Politics Based on Geopolitics? A Proposal for a Geopolitics-Driven En­large­ment Policy’, in Džankić/Kacarska/Keil (eds.), A Year Later, War in Ukraine and … Continue reading

In doctrinal terms, the resulting en­large­ment regime is best un­der­stood as modular con­di­tion­al­ity gov­er­nance char­ac­terised by re­la­tional steering, functional access, and risk-managed integration. Con­di­tion­al­ity no longer derives effectiveness primarily from the promise of accession, but from the continuous modulation of par­tici­pa­tion across policy domains. This enhances flexibility under geopolitical pressure, yet it raises concerns about coherence, transparency, and normative consistency. The modularisation is not merely instrumental but also normative: Com­pli­ance is increasingly evaluated across discrete performance domains, such as sectoral compatibility, administrative reliability, and in­sti­tu­tional resilience, alongside classical rule-of-law and democracy benchmarks. In a modular con­di­tion­al­ity regime, these functional criteria do not merely complement one another; they function as sector-specific proxies for com­pli­ance, enabling selective integration rather than com­pre­hen­sive liberal-democratic consolidation. Reform ex­pec­ta­tions are de­com­posed into policy-specific com­pli­ance bundles, each linked to dif­fer­en­ti­ated access thresholds and reversible par­tici­pa­tion rights. In re­la­tional terms, the content and meaning of EU conditions are continuously redefined through interaction and contestation.^[50]Slootmaeckers, (Fn 34). This also alters the re­la­tion­ship between con­di­tion­al­ity and domestic politics in candidate countries. Classical ex-ante con­di­tion­al­ity relied on the mobilisation potential of a distant but symbolically powerful reward. Modular con­di­tion­al­ity operates through immediate incentives like funding tranches, market access, and programme par­tici­pa­tion, whose effects are more technocratic and less identity-laden. Domestic engagement increasingly takes the form of negotiation, translation, and tactical adaptation rather than straightforward com­pli­ance and re­sis­tance. At the same time, sectoral integration can heighten suspicion precisely because it blurs boundaries without guaranteeing a trajectory: absent a credible linkage to membership progression, intermediate inclusion may be perceived as looser cooperation rather than as predictable accession. The Western Balkans experience adapts to the rationality of such suspicion: where accession is repeatedly stalled, domestic actors learn that com­pli­ance signals can be politically discounted, incentivising performative alignment rather than costly trans­for­ma­tion.^[51]Petrovic/Tzifakis, (Fn. 39).

A final structural implication follows. Modular con­di­tion­al­ity can serve as a gov­er­nance substitute when accession credibility is weakened: sectoral integration and staged funding preserve EU influence and regulatory con­ver­gence without resolving accession deadlock. In this configuration, the promise of en­large­ment is re-functionalised as a gov­er­nance resource. Precisely because accession remains formally open yet substantially deferred (due to EU-internal veto dynamics, reform requirements, but also a lack of trans­for­ma­tion in candidate countries), the membership perspective shifts from a credible endpoint to a flexible instrument of influence. The en­large­ment promise retains its governing effect not through its imminent fulfilment, but through its indefinite postponement, which allows the EU to leverage anticipation and partial inclusion as tools of regulatory and political steering.

E. Conclusion

The emerging en­large­ment regime may therefore be un­der­stood as modular con­di­tion­al­ity gov­er­nance under geopolitical competition: re­la­tional steering through differentiated access, continuous recalibration of rewards, and boundary adjustments designed to manage systemic exposure. EU en­large­ment is increasingly mediated through an investment-centred gov­er­nance architecture, in which the EU Commission’s DG ENEST coordinates de­vel­op­ment banks and blended finance instruments to steer reforms and integration pathways, further reinforcing modular con­di­tion­al­ity and strength­en­ing executive steering and bankability with a risk of weakening domestic own­er­ship and long-term trans­for­ma­tive capacity.^[52]M. Thiemann, D. Mocanu, D. Piroska, The Rise of the European En­large­ment State: Blended Finance, Development Banks and the New Modalities of EU Accession, Journal of European Public Policy … Continue reading Against this background, “what it takes to join the EU” can no longer be reduced to acquis com­pli­ance. Instead, accession increasingly requires navigating a dis­cre­tionary, unanimity-gated decision structure in which con­di­tion­al­ity is implemented through functional par­tici­pa­tion and sectoral access regimes, whose allocation remains politically contestable. The critical implication is clear: where con­di­tion­al­ity operates through multiple partly disconnected channels, its trans­for­ma­tive promise becomes harder to sustain. Geopolitical en­large­ment may restore the plausibility of the membership promise, but if it simultaneously erodes the credibility of exclusion for non-com­pli­ance, it risks drifting toward integration by strategic necessity with attenuated “good gov­er­nance” discipline.^[53]Schimmelfennig, (Fn. 37).

At the same time, the experience of the 2004 and 2007 en­large­ments cautions against overly pessimistic assessments of en­large­ment’s in­sti­tu­tional con­se­quences. Fears that eastward en­large­ment would undermine the functioning of the EU institutions have largely not materialised. Empirical assessments suggest no generalised negative in­sti­tu­tional effects, but rather partial and sector-specific adjustments.^[54]Mišík/Brusenbauch Meislová, (Fn. 3). Where in­sti­tu­tional gridlock has emerged, it is more closely linked to processes of unexpected autocratisation – most notably in Hungary – than to the increased number of Member States as such. Studies on Central and Eastern European countries further indicate the enduring relevance of pre-accession conditions. Research in sectors such as agriculture suggests that initial conditions and administrative preparedness may have exerted a stronger long-term influence than previously assumed.^[55]A. Jambor, M. Gorton, Twenty Years of EU Accession: Learning Lessons from Central and Eastern European Agriculture and Rural Areas, Agricultural and Food Economics 13 2025. At the same time, a significant lack of knowledge remains in comparative research on en­large­ment effects at sub-national and regional levels, both for the post-2004 Member States and for current candidates. In the present en­large­ment context, the strong geopolitical framing risks obscuring such differentiated, long-term trans­for­ma­tion dynamics.

Looking ahead, the prospects for further en­large­ment depend on two interrelated conditions. First, candidate countries must pursue com­pre­hen­sive reforms to align legal frameworks, in­sti­tu­tional capacities, and societal practices with EU standards, while actively countering the risk of regression, as illustrated in Hungary. Second, the Union itself must apply en­large­ment con­di­tion­al­ity in a consistent and rules-based manner. Gradual accession processes, allowing a step-by-step integration in areas where progress is evident, have proven effective in earlier en­large­ment rounds and remain a viable approach for managing heterogeneity among future applicants. The 20^th anniversary of the 2004 en­large­ment serves as a reminder that the EU’s democratic project requires continuous vigilance, in­sti­tu­tional adaptation, and credible rule-of-law enforcement both within and beyond its borders. The historical comparison of en­large­ment phases highlights a shift in underlying policy logics. While en­large­ment towards Central and Eastern Europe in the 1990s was predominantly guided by a trans­for­ma­tion logic, en­large­ment since follows a stabilisation logic, and since 2022, a demarcation logic aimed at limiting the influence of strategic rivals, combined with a logic of cohabitation that maintains engagement with neighbouring countries without necessarily advancing full integration.^[56]Ghincea/Pleșca, (Fn. 36).

All in all, lessons from the 2004 and 2007 en­large­ments underline the structural limits of con­di­tion­al­ity, as in that period, it depended on a specific social and normative context associated with the “return to Europe”.^[57]Grabbe, (Fn. 5). The EU’s direct political influence declined after accession, even where legal com­pli­ance persisted, as especially in Romania and Bulgaria. Hence, con­di­tion­al­ity is a context-dependent gov­er­nance mechanism whose trans­for­ma­tive capacity weakens once its societal an­chor­ing erodes.

Under geopolitical pressure, en­large­ment shifts from a socially mediated process of trans­for­ma­tion to an executive logic of risk management, un­der­min­ing the social mechanism through which con­di­tion­al­ity generates com­pli­ance. A further consequence is the emergence of a de facto geopolitical hierarchy among accession candidates. As access to integration benefits becomes increasingly mediated by strategic relevance, candidates’ prospects are no longer ordered by reform performance but by their perceived contribution to the Union’s security and geopolitical objectives. This dynamic is acutely perceived in the Western Balkans, where governments fear being structurally relegated in the accession queue as en­large­ment priorities shift eastward. The contrast is instructive: when Hungary’s veto on opening accession ne­go­tia­tions with Ukraine was effectively neutralised through procedural manoeuvring, the signal was unambiguous: unanimity constraints can be overcome where sufficient political will exists. The absence of similar determination in addressing Bulgaria’s long-standing blockage of North Macedonia underscores that such flexibility is not evenly distributed among the Member States across the candidate countries but selectively activated in line with geopolitical salience.

This asymmetry feeds back into the logic of modular con­di­tion­al­ity itself: it reinforces perceptions of dis­cre­tionary en­large­ment gov­er­nance, weakens the stabilising function of accession con­di­tion­al­ity, and risks entrenching differentiated trajectories of integration in which strategic indispensability, rather than reform credibility alone, becomes a key determinant of progress. This logic is also visible in recent proposals to fast-track Ukraine’s accession by recalibrating both eligibility and procedure, most notably through security-coding accession criteria, Commission-driven chapter advancement subject to reverse qualified majority blocking, and a model of probationary membership that shifts parts of the reform burden into structured post-accession transition arrange­ments.^[58]Andrew Duff, How Ukraine Should Join the European Union, Verfassungsblog, 26 January 2026, <https://doi.org/10.59704/6d4cfbda61c9dd49> (accessed 19.1.2026).