A new BiEPAG analysis by Jovana Marović and Odeta Barbullushi calls on the European Union to transform accession treaties into strong instruments of reform and accountability, rather than solutions that lead to limited, “lighter,” or second-tier forms of membership. The authors warn that an approach that keeps Western Balkan countries at the very margins of integration could create a new divide — from the periphery of Europe to the periphery of the European Union itself — thereby contributing to further weakening rather than the much-needed strengthening of the EU. Among the key recommendations are integrating existing instruments into accession treaties, strengthening the link between reforms and financial support, introducing clear and automatic safeguard mechanisms based on measurable results, and preserving full political equality for future member states.

Balkans in Europe Policy Advisory Group (BiEPAG) has published a new analysis titled “Enforcement, Incentives, and the Missing Link: How Accession Treaties Can Strengthen Europe,” which addresses how the European Union can make the enlargement process both more credible and more effective. The analysis draws on lessons from previous enlargements and newly developed instruments for the Western Balkans, highlighting a long-standing issue: pressure and conditionality are strongest before membership, but weaken significantly after accession. This creates space for reform stagnation and undermines confidence in the EU’s transformative power.

Rather than promoting ideas of permanently differentiated levels of membership or limiting the rights of new member states, the authors argue for a smarter and more decisive use of the existing legal framework. Accession treaties already contain safeguard mechanisms and transitional arrangements, but these are not sufficiently connected to rule-of-law protection instruments and reform incentives developed by the EU in recent years. By strengthening these linkages, EU accession can become a powerful driver of institutional change that remains sustainable even after membership.

The analysis places particular emphasis on financial conditionality as the most effective catalyst for change. The experience of both member states and candidate countries shows that monitoring and reporting alone rarely deliver tangible results, whereas a clear link between reforms and access to EU funds produces visible effects. The authors also propose the introduction of objective criteria that would allow safeguard measures to be triggered automatically, without prolonged political blockages, thereby making the process more predictable and fair for all states.

At the same time, the analysis warns that creating permanently differentiated membership would weaken the very idea of European unity. The European Union, the authors argue, should preserve the principle of full political equality, while embedding stronger accountability mechanisms directly into accession treaties. Such an approach would ensure that enlargement remains geopolitically credible while safeguarding the Union’s democratic values and institutional stability.

The new analysis comes at a moment when enlargement has once again returned to the top of the EU’s political agenda. BiEPAG stresses that the solution does not lie in lowering membership standards or creating new divisions among states, but in strengthening the instruments that ensure accession represents genuine transformation — both for the countries joining and for the European Union itself.