Should the countries of the Western Balkans join the European Union at the same time, as suggested by Serbian President Aleksandar Vučić?
Progress in the EU enlargement process will be the main topic at the meeting on 17 December 2025 in Brussels between EU leaders and those of the Western Balkans.
Following the wars of the 1990s that devastated the Balkans, the European Union pledged in 2003 to integrate seven Western Balkan countries into the bloc: Albania, Bosnia and Herzegovina, Croatia, Kosovo, Montenegro, North Macedonia, and Serbia.
Croatia joined the EU ten years later.
With the exception of Kosovo, which applied for membership in 2022, the other five countries are already officially EU candidate states.
How are developments unfolding?
More than a decade after Croatia joined the EU, enlargement in Brussels appears closer than ever. The EU has clearly reaffirmed its commitment to enlargement, and the key question is no longer whether new accessions will happen, but which Western Balkan countries are ready to move forward and which will fall behind.
Montenegro, the smallest of the five candidate countries, is widely regarded as the frontrunner in the accession process, with Albania following closely behind.
According to EU Enlargement Commissioner Marta Kos, Montenegro could technically complete negotiations by the end of 2026, while Albania could do so a year later.
“We would then need another one to one and a half years for the ratification process. So I am genuinely optimistic that during my mandate, which ends in 2029, the European Union could have at least two new member states,” Kos recently told DW.
In Serbia, which is economically the strongest candidate in the region, momentum for reforms has noticeably slowed. In response, President Vučić suggested last week—ahead of his trip to Brussels for talks on Serbia’s EU progress—that all Western Balkan countries should join the EU simultaneously.
But is such a scenario feasible, and would it be acceptable to Serbia’s neighbors and the EU itself?
Montenegro leads the way
The EU enlargement process in the Western Balkans has been slow for several reasons. On the one hand, the region continues to face unresolved bilateral disputes, shortcomings in the rule of law, and high levels of corruption. On the other hand, EU member states have shown hesitation and “enlargement fatigue.”
After years of stagnation, Montenegro accelerated key reforms two years ago and built broad political consensus around EU membership. Both Podgorica and Brussels are now aiming to complete the accession process as swiftly as possible.
Recently, Montenegro reached a significant milestone by closing five accession chapters—an essential prerequisite for EU membership. However, the country still needs to deliver final convictions in high-level corruption and organized crime cases, appoint key judicial officials, and fill senior leadership vacancies in major institutions.
Domestic critics argue that reforms are rushed and superficial.
“No one can seriously claim that a system can be fundamentally transformed within just a few years,” said Montenegro’s Minister for European Integration, Maida Gorčević.
“Criticism is legitimate if it accelerates reforms, but it is important to stress that progress today is measured by clear European benchmarks, not political impressions, and Montenegro’s progress is objectively confirmed by EU institutions,” she told DW.
Albania’s progress
Meanwhile, Albania has also accelerated its reform efforts.
While the European Commission acknowledges progress in judicial reform, it has emphasized the need for further efforts to combat corruption and strengthen the rule of law.
Political analyst Florian Bieber notes that success is far from guaranteed and that sustainable reforms are still needed.
“Albania is undertaking many reforms, at least formally, but in a context where there is a very strong leader like Edi Rama, there are certainly serious democratic shortcomings. So there are reservations, and it remains unclear whether Albania will be able to close that gap and truly be ready at the same time as Montenegro,” Bieber told DW.
Why does the EU want to enlarge?
For the European Union, enlargement is a matter of geostrategy and credibility.
According to a report by the European Policy Centre, “integrating Montenegro would be a low-risk, high-impact way to demonstrate that the EU can deliver on its promises, reinforcing trust in its leadership during times of geopolitical uncertainty.”
“We are paying the price for not having integrated these countries when they first wanted to join, by leaving a region unstable,” Commissioner Kos told DW.
EU enlargement is also seen as a geostrategic investment in Europe’s security and prosperity, said Tinatin Akhvlediani, a researcher at the EU Foreign Policy Unit of the Centre for European Policy Studies.
“If the Union does not accept these states, other powers may step in and exploit the region as leverage against the EU, including Russia and China,” Akhvlediani told DW.
How is the Serbian proposal viewed?
Given the differing pace of progress toward EU membership across the region, where does this leave Aleksandar Vučić and his proposal for simultaneous accession?
Many analysts interpret the proposal as an attempt to slow down the overall integration process.
Within the European Commission, there appears to be little enthusiasm for the idea.
“Accession is a merit-based process. Each candidate joins when it is ready and has met the conditions and criteria set out in the EU Treaties, including the Copenhagen criteria. There are no predetermined timelines. The process is driven by reforms and the delivery of sustainable results,” a Commission spokesperson told DW.
Each country charts its own course
Both Tinatin Akhvlediani and Florian Bieber emphasize that EU enlargement has always followed the “regatta principle,” meaning that each candidate country charts its own course and advances based on its merits, reforms, and fulfillment of technical criteria.
However, Bieber notes that simultaneous accession does have some advantages.
“It would avoid creating new external EU borders between Western Balkan countries and prevent the import of bilateral disputes into the EU,” he said.
“However,” Bieber added, “there are serious drawbacks, because the pace of the slowest member—or candidate, more precisely—would determine the speed for everyone. So if Montenegro is ready to join the EU in the coming years, this could be delayed by countries such as Bosnia and Herzegovina or Kosovo, potentially by a decade or more.”
Montenegro is not willing to wait
The Albanian prime minister’s office had no comment on Vučić’s proposal at the time of publication.
Montenegro, however, reacted immediately, making clear that it intends to move forward.
“Montenegro does not want to wait for anyone, nor does it expect anyone to wait for us,” Minister Gorčević said. “We are leaders in this process and we want to join the European Union when our results show that we are ready and that we deserve membership.”
Late on Tuesday evening (16 December 2025), it was announced that Serbia would not participate in Wednesday’s summit in Brussels.
Vučić personally announced the decision, stating that he was acting to protect Serbia’s interests and adding that he made the decision “so that no one else would be blamed and the government would not be subjected to any pressure.” /DW/
