Russia’s invasion of Ukraine made EU enlargement a strategic necessity without altering its merit-based rules. The tension between urgency and strict conditionality endures. Matis Poussardin argues that EU agencies can bridge this gap by enabling gradual, sector-specific participation in EU governance without lowering accession standards

Geopolitics won’t wait, reform can’t hurry  

Russia’s unprovoked war against Ukraine has turned enlargement from a largely technocratic exercise into a geopolitical imperative. In record time, the EU granted candidate status to Ukraine, Moldova, and Georgia, reinvigorating stalled processes in the Western Balkans. 

Yet beneath this renewed momentum lies a familiar structural constraint. Enlargement remains long, technical, and deeply transformative. Candidate countries must reform judicial systems, overhaul public administrations, and align with the vast and intricate EU acquis. Political will in Brussels has grown, but the fundamentals have not changed. Accession still follows a strict merit-based logic, with no real shortcuts — a reality that increasingly frustrates societies asked to wait. 

The result is a persistent tension between the EU’s strategic urgency and the demanding pace of reform required for membership.

EU accession still follows a merit-based logic with no real shortcuts. The societies being asked to wait are growing increasingly frustrated

Making differentiated integration real 

Frank Schimmelfennig argued in this series that differentiated integration offers a way out of this dilemma. By granting candidate countries 'checkpoint' rewards as they advance in their reforms, the EU can preserve merit-based conditionality while making progress more visible and politically meaningful. 

The logic of gradual integration is already on the table. The challenge now is to operationalise it in concrete institutional terms, identifying where and how candidate countries can participate meaningfully in EU structures before full membership. 

EU agencies as vessels of differentiated integration 

Decentralised EU agencies (hereafter EU agencies) have become central pillars of EU governance. Nearly forty agencies operate across almost all sectors of the acquis: justice and home affairs, banking supervision, energy cooperation, and many more. They play a role in every aspect of EU governance, from the development of EU acquis to its implementation and enforcement.

EU agencies play a role in every aspect of EU governance, from the development of EU acquis to its implementation and enforcement

EU agencies are particularly well-suited venues for differentiated integration to take place. They help tackle the enlargement dilemma for two main reasons.

1. The regulatory dimension of EU agencies

EU agencies possess the sector-specific expertise required to support candidate countries in the adoption and implementation of EU rules. Enlargement requires strong administrative capacity to be able to effectively adopt and implement EU acquis. 

EU agencies provide capacity-building activities for the candidate countries through dedicated training programmes, observer status in operational activities of the agencies or peer reviews of their administrative practices. Through these interactions, candidate country officials familiarise themselves with EU standards required for enlargement well before formal full membership. This offers strong support for their path toward EU membership.  

In this regard, EU agencies are not very different from other EU policies and programmes. However, beyond this administrative support, EU agencies add an important organisational dimension.

2. EU agencies' organisational dimension

EU agencies are relatively permeable institutions. In central EU bodies, participation generally coincides with full membership. Unlike such bodies, agencies often allow third countries to take part in decision-making structures, typically without voting rights. Such participation is granted on a case-by-case, sector-by-sector basis and can be calibrated to reflect progress in specific policy areas. 

This flexibility makes EU agencies well suited to differentiated participation. A candidate country advancing in the electricity acquis, for example, could join the relevant EU energy agency. Similarly, progress in financial supervision could open access to EU financial agencies. Reform progress would thus be rewarded not only through the provisional closure of negotiation chapters, but through structured access to EU bodies. 

Beyond the symbolic value of participating in EU institutions, important for sustaining public support, agency involvement enables candidate countries to contribute to the preparation, implementation, and enforcement of the very same acquis they are expected to adopt. 

EU agencies therefore complement the traditional regulatory dimension of enlargement with a tangible organisational one, narrowing the gap between candidacy and membership. They provide a practical way to reconcile the EU’s strategic interest in enlargement with high accession standards and a merit-based approach. 

Despite this potential, the EU has not systematically mobilised agencies as enlargement instruments. My research shows that participation remains uneven across sectors and countries, and often depends on the preferences and autonomy of individual agencies. 

Enlargement beyond rhetoric 

Russia’s full-scale invasion of Ukraine injected new momentum into a policy that had long drifted. Many now frame enlargement as a geopolitical necessity. At the same time, European leaders insist that accession must remain strictly merit-based. These objectives can pull in different directions, but, as others in this series have argued, gradual integration offers a way to reconcile them.

EU agencies are vehicles for regulatory export, and permeable entry points into EU governance

I advance a concrete institutional proposal. EU agencies can operationalise differentiated integration. They function both as vehicles for regulatory export and as permeable entry points into EU governance, making them strategic instruments for the next phase of enlargement. 

By involving candidate countries in sectoral governance structures, EU agencies can transform enlargement from a distant promise into a structured, progressive path toward full integration, without lowering standards or bypassing conditions. 

The political window created by Russia’s invasion will not remain open indefinitely. If the EU intends to act strategically, it must move beyond rhetoric, and deploy the instruments already at its disposal.

No.37 in a Loop series on 🧭 EU enlargement dilemmas