Steven BLOCKMANS

Deputy Director of ICDS, the International Centre for Defence and Security (Tallinn), Associate Senior Fellow and previously Research Director at CEPS (Brussels). He is also a Visiting Professor at the College of Europe and Editor-in-Chief of the European Foreign Affairs

The EU needs a credible plan for governing an enlarged Union, not an assumption that its institutions will somehow adapt afterwards.

The European Union cannot afford to grow at the expense of its ability to act. Russia’s protracted war against Ukraine is the most visible sign of a more fragmented geopolitical landscape in which Moscow, as well as Beijing and Washington, increasingly exert pressure on European unity on enlargement. Meanwhile, regional powers like Turkey and some Gulf states further complicate relations in and with EU candidate countries. Enlargement is therefore not only about extending the EU’s borders; it is a test of strategic autonomy in deepening the Union. Admitting new members to bloated institutions, some of which are already vulnerable to national vetoes, risks turning a geopolitical necessity into a governance crisis. 

The European Commission’s October 2026 strategy, Preparing for a wider European Union, argues that the EU can prepare for enlargement largely within its existing treaty framework. But legal flexibility alone cannot answer the central political question: how can a larger EU act decisively when external actors can exploit its internal divisions? The answer is straightforward: enlargement and institutional reform must advance together. The EU should expand without sacrificing its capacity to act.

Stop vetoes from derailing enlargement

A larger Union will make decision-making harder unless governments address the risk that national vetoes will obstruct common action. Existing treaty provisions must be used, and member states should agree where further change is needed.

The European Council should commit to qualified majority voting (QMV) for all intermediate decisions in the pre-accession process, while retaining unanimity for the opening and final decisions on membership. This would limit the ability of bilateral disputes or domestic political calculations to derail a process that should be based on candidates’ merits and progress.

Member states should also make fuller use of ‘passerelle clauses’ and constructive abstention to facilitate the adoption of a new common foreign and security policy. Where treaties permit, QMV should be used more consistently for decisions that implement agreed common policy, including those on sanctions and civilian missions.

Going beyond what is already prescribed in treaty law, the two thirds of EU countries that call themselves ‘friends of QMV’ should again table the proposal to mainstream QMV across sensitive areas such as foreign policy and fiscal matters, while protecting essential national interests by putting emergency brakes in place. The aim is to prevent new forms of paralysis, not to silence smaller states.

Make gradual integration a credible route to membership

Gradual integration should be a structured pathway to full membership, not a waiting room offering selective benefits without a credible prospect of accession. Participation in EU programmes, policy discussions and institutions should expand in line with verified progress across all accession criteria. Respect for democracy and the rule of law must carry more weight than technical and economic alignment. Progress should bring tangible benefits, while regression should trigger clear and proportionate consequences.

The EU should define how participation deepens as accession approaches. Once an accession treaty is signed, candidates should receive the widest participation rights compatible with their status, including parliamentary observers, members of expert groups and shadow Commissioners. This would help acceding states prepare for EU responsibilities while allowing existing institutions to prepare for enlargement.

Build safeguards into accession treaties

Future accession treaties should include clear and legally grounded safeguards against serious post-accession backsliding on the fundamentals of democracy and the rule of law. These measures must be proportionate, based on objectively identifiable conditions, regularly reviewed and subject to judicial scrutiny. They should be time-limited where appropriate and removed or amended when the underlying problems are remedied. Their purpose must be to protect the EU’s constitutional order, not to create second-class membership or give existing members an unrestricted political lever over newcomers.

Agreeing on safeguards before accession would clarify the membership obligations and reinforce the principle that they remain binding after accession.

Prepare the institutions for an enlarged EU

Institutional reform cannot wait until enlargement is imminent. While the accession of small candidate countries like Montenegro, Albania and Moldova may not require changing the rules underpinning the EU’s current institutional design, the gradual and eventually full integration of Ukraine would, given the size of the country, demand a politically difficult renegotiation of the balance within the main institutions of the EU.

This pertains as much to the weighted votes in the Council, as to the treaty ceiling on the number of members of the European Parliament, and the size of the Commission. Member states should scrap the protocol added to convince Ireland to ratify the Lisbon Treaty, and apply the treaty provision allowing a college smaller than the number of member states, with an equal rotation system reflecting the EU’s geographical and demographic diversity.

Governments should use existing treaty tools wherever possible and identify early the changes that accession treaties cannot cater for. Delaying these decisions will only make agreement harder under political pressure.

Enlarge with a plan for governing

The European Council, which is slated to have a strategic discussion about enlargement mid-October with a view to adopting formal conclusions in December, should commit to reforming regular decision-making alongside accession negotiations, providing candidates with meaningful but conditional participation, establishing proportionate safeguards against backsliding, and preparing the Council, Commission and European Parliament for a larger membership.

Russia’s aggression, China’s coercion, American fickleness and the competing interests of regional powers all strengthen the case for an EU that shapes events rather than merely reacts to them.

Enlargement alone will not deliver that capacity, and institutional reform cannot guarantee unity. But adding members while leaving avoidable veto opportunities and institutional weaknesses unresolved would compound risks the EU already understands. Every step towards a wider Union must deepen its ability to decide, act, and uphold its rules. The EU needs a credible plan for governing an enlarged Union, not an assumption that its institutions will somehow adapt afterwards.

Photo credits: European Union 2026