The Commission has now put an indicative date on an accession treaty’s signature. The harder date is the one no roadmap can guarantee: when the last member state ratifies. Montenegro’s roadmap runs from a final negotiating conference in December 2026 to signature in June 2027; Albania, Moldova and Ukraine have roadmaps of their own.

Reaching signature would be an achievement in itself, and it is not guaranteed. Every remaining chapter still needs the agreement of all member states, and so will the treaty text. With elections due in 2027 in Montenegro and many member states, including France, Greece, Italy, Poland and Slovakia, treating signature as a strategic milestone makes sense: waiting for certainty could mean missing a window that may not reopen. A signed treaty locks in years of work and raises the cost of walking away. It is a far better position than leaving everything to the vagaries of national politics, in candidate countries and member states.

But while a signature can make refusal harder to justify, it cannot make ratification inevitable. The task is to turn this opportunity into membership, and that requires a ratification strategy, not just momentum.

Making the interval count

The roadmaps give the transition towards membership practical substance. After the final negotiating conference, Montenegro would be kept informed of Council and Commission initiatives; after signature, the European Parliament may invite Montenegro’s parliament to appoint observers and the Commission will examine “structured political participation” in its activities. The scope of that participation remains to be settled: it must be meaningful enough to build experience and confidence if it is to strengthen the case for ratification.

But participation is not membership. Observers have no vote, and further benefits depend on what is agreed. Such arrangements should prepare for accession and build confidence in it, with clear expectations about what participating countries must deliver and what they can expect in return.

Successful cooperation could, however, also create a perverse incentive to postpone membership. If practical cooperation works well, reluctant member states may find delay easier to tolerate. Candidates could deliver reforms and prove their usefulness while remaining outside for reasons they cannot resolve. The arrangements intended to ease the path to membership could become a comfortable waiting room for the Union.

A related question concerns gradual integration. Access could be made conditional partly on “progress on the enlargement process”. If that means verified reforms, the condition is sensible. If it means formal negotiating steps, an unrelated veto could also block sectoral integration, the very instrument meant to sustain reform when talks stall. The Commission should clarify what progress means.

Turning momentum into consent

Avoiding the waiting room requires three commitments.

First, member states must take political ownership of the timetable. Albania’s roadmap calls itself an anchor for “both Albania and the member states”. It foresees 15-chapter closures, alongside closure of the fundamentals cluster, in the second half of 2027: a demanding timetable that also requires member states to act unanimously. Even for Montenegro, where the Commission considers all closing benchmarks met, concluding negotiations still requires member state agreement on the remaining chapters and accession terms. Yet while the package calls for work on decision-making and refers back to October’s Communication, it does not explain how the proposal for qualified majority voting at intermediate negotiating stages will be taken forward. The Commission should report clearly on outstanding EU decisions and unfinished reforms. A missed milestone should not automatically be read as a candidate’s failure.

Second, governments must translate the Commission’s call to lead national debates into preparation for ratification, building support broad enough to survive a change of government. France illustrates the difficulty: a referendum is the default unless demanding parliamentary supermajority requirements are met. Governments supporting enlargement should explain why admitting a prepared country serves their citizens’ interests, engage parliamentary parties and address concrete concerns. Experience gained through participation can support that case, but political leaders must make it.

Third, confidence in lasting reforms must be sustained through accession. The Commission considers Montenegro’s closing benchmarks met, while its country report still identifies unfinished anti-corruption constitutional amendments and weaknesses in implementation. Meeting closing benchmarks does not mean that every membership preparation is complete. The roadmap therefore envisages continued monitoring and proposes targeted measures, with a possible postponement clause as a last resort. These tools must target backsliding, not democratic alternation, and leave a clear route to accession once shortcomings are remedied.

Safeguards matter here for a reason often missed. Beyond protecting against a new member’s backsliding, credible safeguards can help secure consent by reducing concerns about the EU’s ability to respond if things go wrong. Member states are less likely to hesitate, or to veto, when they trust that such tools work. Since Montenegro’s treaty is intended to be the model for subsequent accessions, its triggers, measures and exit conditions must be clear.

Yet safeguards aimed only at newcomers face a dilemma: temporary ones may expire before the risks have been resolved; permanent ones would create second-class membership. The way out is to move from exceptional control of new members to system integrity across the Union: common rules that apply to all members alike, and decision-making reforms that reduce opportunities for unilateral obstruction, by old members as well as new. Montenegro cannot carry the Union’s insurance alone.

Delivering membership

The roadmaps deserve support because they make the next enlargement a concrete prospect. They should be judged both by whether candidates meet their commitments and by whether the Union acts when they do. Its own readiness deserves the same scrutiny. Finding that most policies can accommodate a larger membership says little about how a Union of 28 or more will take decisions.

The opportunity is to use the period before membership to earn and organise consent. The danger is to assume that successful participation will produce it automatically. A treaty signature should begin a concerted effort to complete accession, with governments taking responsibility for the decisions that remain. It should not mark the point at which the Union becomes content to wait.

Corina Stratulat is Associate Director and Head of the European Politics and Institutions Programme

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