Rethinking the EU’s Expansion Dilemmas

Rethinking the EU’s Expansion Dilemmas: A phased integration model with institutional capacity

How phased integration and decision-making reforms preserve cohesion and

effectiveness

Burak Baran

Miranda Simón Rivera

The EU faces a dilemma. In the current political sphere EU enlargement is necessary to ensure regional stability and deter external threats, however a possible enlargement risks undermining internal cohesion and decision making capacity of the Union. We argue that enlargement without institutional changes would further EU governance inefficiencies and deepen internal divisions.

Analysing recent cases like vetoes in EU foreign policy and disputes regarding rule of law among member states, this paper demonstrates that unanimity based voting is limiting effectiveness of the EU. A new wave of EU enlargement would further increase the inefficiencies.

To address the findings, this policy paper proposes a deepening before enlargement approach through an integration model called ‘European Political Sphere’, where candidates would get gradual access in EU institutions and frameworks based on conditional and measured approaches. In parallel, this paper suggests extending QMV in key policy areas to reduce decision-making blockages.

All together, the proposed reforms would transform enlargement into a controlled and reversible process, unlike the existing binary process. Such a proposal further increases the EU’s institutional capacity while enhancing its role as a coherent geopolitical player.

As of 2026, there are 10 countries in the context of European enlargement that matters. Albania, Bosnia and Herzegovina, Kosovo, Montenegro, North Macedonia, Serbia, Turkey, Georgia, Moldova and Ukraine. Accession negotiations into the EU are complicated, requiring negotiations across 35 chapters on top of meeting the Copenhagen Criteria. While a possible enlargement could offer geopolitical advantages, it could possibly raise issues about its capacity to function effectively. The Union already faces issues regarding decision making and effective governance, shown by Hungary’s veto on sanctions against Russia. The Union also faces rule-of-law challenges within existing members, demonstrated by Poland and Hungary regarding judicial independence and democratic standards. Such tensions undermine the credibility of the Union and raise concerns about admitting new member states. States preferring expansion on one side, and states advocating for deeper institutional reforms on the other side could further increase the already existing internal division within the Union. As membership of the Union increases, differences in issues such as threat perception, economic priorities and democratic standards could be questioned even further; complicating institutional practices. This leaves the EU with a dilemma: how can the Union pursue enlargement without weakening its internal cohesion and governance any further?

The EU should pursue enlargement through a conditional approach that is tied to institutional reforms that make decision-making and rule-of-law enforcement more powerful.

We find that EU enlargement is necessary geopolitically for regional stability and security. As shown by the war in Ukraine, the war has reshaped the understanding of European security dynamics. It has demonstrated that non-EU members are more vulnerable to external aggression. Enlargement can function as a tool of alignment with the West and mechanism of protection by reducing power vacuum countries like Russia could exploit. In the Western Balkans, existing ethnic tension and unresolved countries such as Bosnia’s internal division and Serbia-Kosovo dispute, highlight risks that the EU could face with absence of credible accession prospects. Enlargement incentivizes democratization efforts and institutional reform while embedding states within a cooperative and rule-based framework.

The existing institutional structure of the EU constrains effective decision making as membership expands. The requirement of unanimity in EU foreign policy and sanctions create incentive for individual states to block or delay collective action as demonstrated by Hungary. Hungary has illustrated how veto could be used as a bargaining tool and undermine coherence and responsiveness of the Union. As membership increases, the number of potential veto actors also grows, leading to slower decision making and longer negotiations. This therefore decreases the EU’s ability to respond to crises effectively.

Enlargement without institutional reforms in the Union could weaken EU governance and cohesion. While enlargement can enhance geopolitical stability, expanding the Union under current frameworks would intensify decision making inefficiencies and further expand internal divisions. Without reforms to address unanimity and governance capacity of the Union, the EU risks being less effective internally and externally, undermining its ability to act as a strategic actor.

We suggest that the EU implements a European Political Sphere (EPS) as a phased integration framework. This would start treating the EU as a graduated system rather than a club. This framework allows candidates to integrate based on performance. The EPS would consist of multiple levels of integration. Each level would be determined through a ranking system consisting of measurement of rule of law, accountability and institutional strength. As states improve, they would gain deeper access to EU institutions, ultimately leading to being a full member. Unlike the current accession processes, the EPS ensures continuous conditionality and gradual integration. This prevents risks associated with premature enlargement.

Within this proposed framework, states would participate in security coordination, strategic planning and intelligence sharing - while aligning with common CFSP policy positions. Candidate states would not possess veto powers or access to high level activities like the Eurozone. This proposed model guarantees early geopolitical alignment and de facto

security integration. This would be used as a tool to counter external influence from third parties such as Russia and China.

This framework would operate through four stages. During the first stage, candidates would align strategically with EU foreign policy. During the second stage, candidate states would be involved in deeper security integration, including intelligence and crisis coordination. Third, states would gain partial access to the EU market and participate as observers in institutional settings. During the fourth and the final stage, candidates would gain full membership rights and access to EU funds, ensuring a smooth transition.

The EPS would incentivize members and non-member states of the EU to maintain democratic standards within the country. This framework would act as a dynamic and reversible ladder. States can progress further through reforms and democratic practices, but also move downwards if certain standards are not met or democratic backsliding occurs. Enforcement mechanisms to this would include monitoring, conditional funding and suspension of voting rights - without the need of unanimity. In cases where a state may disagree with such decisions, they would have the right to appeal to the ECJ. This would introduce credible costs to non-compliance and address the current limitations the EU faces in enforcing post-accession accountability, as demonstrated by Hungary.

In times of crisis, the EU’s reliance on unanimity - especially in foreign policy and sanctions - constrains its ability to act effectively. As the EU expands, chances of policy deadlocks and strategic vetoes will increase, undermining internal coherence and external credibility. As a result, we believe that reforming the decision-making process is essential to ensure that enlargement doesn’t come at the cost of governability.

First, we propose that QMV should be extended to foreign policy and sanctions. Under this proposal, decisions would require 55% of member states representing 65% of the EU population. This would balance efficiency and legitimacy, preventing single-state and strategic vetoes, while requiring significant support. Extending QMV would prevent a single state to use veto power as a bargaining tool, and encourage coalition-building.

Secondly, we propose that a reverse majority rule should be introduced to the EU decision-making framework. Under this, proposals would be adopted by default unless a qualified majority votes against them. Instead of states benefitting from obstruction, states would now have to justify opposition to coalition - reversing the current structure. As a result, incentives in decision making would shift from strategic veto to use of accountability. This would improve the efficiency and consistency of EU actions.

Thirdly, we propose that the EU should implement a crisis fast-track mechanism that would be used in times of crisis such as armed conflict, major security threats or severe economic shocks. In such cases, decisions would be taken by QMV with a limited deliberation window and immediate implementation. In current settings, tendency of the EU toward delayed and fragmented crisis response diminishes the coherence and deterrence of the Union. This framework would address this issue and enhance the Union’s capacity to act swiftly and coherently in times of crisis.

Lastly, we propose that sanctions should be explicitly made veto-free and integrated into QMV. Unanimity has been preserved in sanctions, however it has consistently and repeatedly undermined the EU’s efforts to respond decisively to threats. Allowing sanctions to be adopted through QMV or reverse majority procedures would increase speed, credibility and predictability of the Union while reducing internal fragmentations.

Taken together, the proposed reforms would transform the EU from a consensus constrained actor into a decisive global player without reducing democratic legitimacy.

Throughout this paper, we have demonstrated that the EU faces a dilemma. A dilemma where enlargement is necessary, but current institutional rules and settings risks undermining cohesion and decision making capacity of the Union. The War in Ukraine and instability in the Western Balkans have repeatedly shown that delaying enlargement can have strategic costs, while existing governance challenges like the rule of law and unanimity constrains reveal the limitations of the existing system.

Throughout this paper, we have argued that enlargement and deepening must happen at the same time. With this phased and conditional approach being implemented through the EPS, it creates an environment for step-by-step integration while preserving oversight and accountability. At the same time, reforms to decision-making processes through implementation of QMV, reverse majority rule, and crisis fast-track ensures that an expanded Union with more members can remain effective and responsive.

Taken together, these measures transform enlargement from a binary decision to a structured and reversible process. Ultimately, the EU’s future doesn’t depend on either deepening or widening, but rather aligning both of them through reforms, ensuring that enlargement complements and reinforces the EU’s role as a credible geopolitical actor.