The problem with the EU’s current enlargement policy is not so much bilateral disputes as the fact that the principle of unanimity has gradually become a tool for political blackmail. In previous waves of enlargement, during the accession of Spain, Poland or even the United Kingdom, the process was often accompanied by disputes, doubts and internal negotiations, but no Member State used its veto as a means of blocking the accession itself.
The situation changed particularly dramatically with the start of enlargement to the Western Balkans, when the abuse of the unanimity principle began to directly influence the course of negotiations for the first time. Since then, bilateral disputes have gradually become an informal, embedded feature of the European integration architecture and a lever of political pressure.The most striking example was North Macedonia, whose accession process was blocked for years by Greece and Bulgaria due to disputes over its name, language and historical heritage. For the first time in the history of the EU, the enlargement process itself was held hostage not only by an institutional instrument – unanimity – but also by unresolved bilateral disputes.
As a result, the principle that once guaranteed the equality of member states and was supposed to ensure fairness in decision-making has turned into a political barrier that allows individual governments to use it to achieve their own goals. Issues of historical memory, language rights or identity are increasingly entering a sphere that should remain technical – the process of negotiations on approximation to the acquis. Thus, the technical procedure has gradually turned into a geopolitical field for blockages.
The turning point was the accession of Cyprus, which effectively institutionalised the conflict with a state outside the Union. Since then, the EU has tried to remain neutral in bilateral disputes, but this restraint has only deepened the political dependence of the enlargement process on the will of individual capitals.
Today, the decision to open or close negotiation clusters remains a political rather than a legal act. The founding treaties (TEU and TFEU) do not contain any provisions requiring unanimity at intermediate stages of negotiations — it is enshrined only in special negotiating frameworks. This creates a ‘grey area’ between law and politics, where even a minor disagreement can paralyse European integration progress.
Examples of arbitration between Slovenia and Croatia or dialogue between Serbia and Kosovo show that, with political will, settlement is possible even in complex conflicts. However, the absence of a common European arbitration or mediation mechanism in the field of enlargement makes these processes fragmented, dependent on the political context and prone to repeated vetoes. This undermines confidence in the EU as an institution capable of acting consistently and strategically.
Current enlargement policy increasingly balances between legal formality and political blackmail. If the European Union wants to maintain its attractiveness and geopolitical weight, it needs to rethink the role of unanimity and introduce effective mechanisms that would prevent its abuse in future rounds of enlargement.
In their article, Steven Blockmans and Butrint Berisha (From Stalemate to Solution: Rethinking EU Approaches to Bilateral Disputes in the Context of Enlargement) propose the creation of an Enlargement Dispute Resolution Mechanism (EDRM). Its function would be to refer disputes between Member States and candidate countries to arbitration with clearly defined deadlines. Issues falling within the scope of the acquis would be dealt with by the European Commission as part of the negotiation process, while foreign policy or identification disputes would be dealt with by independent arbitration or mediation institutions such as the International Court of Justice, the Permanent Court of Arbitration, the Council of Europe (through the Venice Commission) and the OSCE (through the High Commissioner on National Minorities). Ideally, such a mechanism would be approved by the EU Council; if this is politically impossible, it could be adopted as an internal document, backed by a statement from the majority of member states. This would raise the political cost for any actor deviating from the new rules of good neighbourliness.
The idea of creating this mechanism is undoubtedly relevant, but at the same time; however, it presents significant implementation challenges.. The line between the technical and political levels of dispute resolution remains blurred: even formally, arbitration procedures inevitably contain a political component, as they touch on issues of sovereignty, identity and historical memory. In the absence of a clear institutional architecture and guarantees of impartiality, there is a risk that the EDRM will become not an instrument of de-escalation, but a new arena for political competition, with potential attempts by member states to influence its procedural decisions. Therefore, the key task should be not only to create the mechanism itself, but also to ensure its institutional autonomy, procedural transparency and accountability to EU political bodies exclusively within their competence. Only under such conditions can the EDRM become a truly effective and legitimate instrument in the European Union’s enlargement policy.
Alongside the EDRM concept, the study “Reining in the Enlargement Vetoes: The German-Slovenian Non-Paper Under Review” by Strahinja Subotić and Filipa Cvetanova (European Policy Centre, 2025) proposes alternative institutional approaches to minimising the impact of bilateral disputes. The researchers emphasise that the main problem is the abuse of the veto right by member states to promote their own political or historical demands on candidate countries. To limit such practices, they propose reforming the decision-making procedures in the EU Council, in particular by gradually transitioning to a reinforced qualified majority voting (Reinforced QMV) model.
Reinforced QMV requires the support of at least 65% of Member States representing 72% of the EU population and is seen as a more realistic compromise between the efficiency of the decision-making process and the preservation of the principle of consensus.
This approach reduces the risk of blocking the enlargement process through unanimity, but at the same time preserves the significant influence of Member States: each country has 36 potential veto points (972 in total), where a candidate’s progress can be stopped if politically necessary.
In practice, Reinforced QMV means that instead of the standard threshold for a normal qualified majority vote of 15 member states representing around two-thirds of the EU population, the new approach requires 20 member states covering at least 72% of the Union’s population. This higher threshold creates an additional safeguard against narrow political majorities that could push through sensitive decisions without proper consensus, while maintaining the flexibility and predictability of the enlargement process.
Unlike the EDRM, which envisages the creation of a separate arbitration tool, the Subotić and Cvetanova approach focuses on institutionally preventing blockages by improving the internal procedures of the Council of the EU. Both approaches, arbitration-mediation (EDRM) and procedural-institutional (Reinforced QMV), are complementary in their common goal: to depoliticise bilateral disputes and increase the predictability of the enlargement process.
In parallel, the EU should step up its preventive diplomacy, early warning and structured dialogue tools to identify latent disputes before they escalate into political deadlock. It is equally important to review internal decision-making procedures: introducing qualified majority voting (QMV) for technical issues or a collective veto, where blocking is only possible if at least three states oppose it. This would limit the abuse of the veto without formally departing from the principle of unanimity in sensitive areas.
Despite all the difficulties, it is important that initiatives are emerging within the EU aimed at finding compromise solutions to resolve bilateral conflicts. However, discussions alone are not enough — concrete action is needed, otherwise the enlargement policy risks remaining blocked. The effective resolution of bilateral disputes is a strategic prerequisite for stability, trust and political unity within the European Union. Without a clear institutional framework, mechanisms for preventive diplomacy and restrictions on the abuse of the right of veto, the EU risks permanently entrenching the phenomenon of ‘vetocracy’, which undermines its ability to act as a single political actor.
The introduction of the Enlargement Dispute Resolution Mechanism (EDRM) could be the first practical step towards restoring the consistency, predictability and strategic integrity of enlargement policy, both for the European Union itself and for Ukraine, which is a key test of the EU’s ability to act geopolitically, not just procedurally.
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Authors
Liubov Akulenko, Executive director Mariia Holubytska, Junior research fellow |