European Union and Western Balkan leaders have gathered in Montenegro for a summit intended to reinforce the region’s membership prospects, but a security dispute involving Serbia has underlined the political risks still surrounding the EU’s enlargement agenda.
The EU-Western Balkans summit in Tivat is being chaired by European Council President António Costa and hosted by Montenegro. European Commission President Ursula von der Leyen and High Representative Kaja Kallas are also taking part, alongside leaders from the Western Balkans.
The formal theme of the meeting is “shared prosperity and stability of the EU and the Western Balkans”. The underlying issue is more direct: whether the EU can turn renewed geopolitical urgency into a credible accession path for a region that has spent years in the waiting room.
Montenegro is the most advanced candidate. It has opened all 33 negotiating chapters and closed 14, and its government has set a target of joining the EU by 2028. With a population of around 630,000, it would be comparatively easier to absorb than larger candidates. But its progress still depends on reforms in areas including corruption, judicial independence and the rule of law.
That makes Montenegro both a test case and a symbol. If the EU cannot complete accession with a small NATO member that is broadly aligned with the bloc’s foreign policy, it will be harder to convince other candidates that the process is genuinely moving. If it succeeds, Brussels would be able to show that enlargement is still possible under the current rules.
The summit comes as France and Germany are promoting a model of structured gradual integration for candidate countries in the Western Balkans and Moldova. The proposal would allow aspiring members to receive earlier access to parts of the single market and selected EU programmes before full accession, provided they meet the required standards.
The idea is intended to address a long-standing weakness in the enlargement process. Candidate countries are asked to carry out politically difficult reforms, often over many years, while the practical benefits of EU membership remain distant. Gradual integration would offer more immediate rewards, such as participation in energy, research, education, industry, or parts of the emissions trading system, without removing the requirement for full compliance with the EU acquis.
It is also a response to geopolitical pressure. Russia’s war against Ukraine has changed the strategic context of enlargement, while China, Russia, Turkey and Gulf states continue to compete for influence in the Western Balkans. For Brussels, keeping the region outside the Union indefinitely now carries greater political and security costs.
Yet the same summit has also shown why the process remains difficult. Serbia’s security agency advised President Aleksandar Vučić not to travel to Montenegro, citing security concerns amid a dispute between Belgrade and Podgorica. The warning followed the return from Tivat of dozens of passengers linked to Serbia’s ruling Serbian Progressive Party after Montenegrin authorities treated them as a security risk.
The incident has introduced a sharper political edge into what might otherwise have been a familiar enlargement meeting. Serbia remains one of the central countries in the Western Balkans accession process, but its relationship with the EU is complicated by its position on Russia, its domestic political tensions, and the unresolved dispute with Kosovo. The latest friction with Montenegro adds another layer of regional mistrust.
For the EU, this is not a marginal problem. Enlargement in the Western Balkans is not only about aligning laws and closing technical chapters. It also depends on regional cooperation, security confidence, minority rights, border management, judicial independence and the ability of governments to resolve disputes without destabilising the broader process.
Montenegro’s case illustrates both sides of the issue. The country has made clear progress towards accession and is widely regarded as the frontrunner. It joined NATO in 2017, imposed sanctions on Russia after the full-scale invasion of Ukraine, and has aligned itself more closely with Euro-Atlantic policy. At the same time, it still faces unresolved domestic problems linked to organised crime, corruption and institutional reform.
Albania is also seen as a credible candidate, while North Macedonia, Bosnia and Herzegovina, Serbia and Kosovo face different combinations of political and institutional obstacles. The EU’s challenge is to create a process that rewards real progress without allowing partial integration to become a substitute for membership.
That is why the Franco-German proposal is politically sensitive. Earlier access to EU programmes could help sustain reform momentum and make accession more tangible for citizens and businesses. But if it is seen as a halfway house, candidate countries may view it as another way to delay full membership.
The Tivat summit is therefore more than a regional diplomatic meeting. It is a test of whether the EU can combine strategic urgency with strict conditions, and whether Western Balkan governments can treat enlargement as a reform process rather than a symbolic destination.
Montenegro may be closest to the finish line, but the Serbia-Montenegro row shows how easily regional politics can intrude on Brussels’ accession timetable. The EU’s enlargement policy is moving again, but its success will depend on whether political disputes in the region can be contained before they become obstacles to membership itself.
