Croatia Blocks Montenegro’s EU Final Stretch, Leveraging Accession to Settle Historical Scores

Since July, Zagreb has blocked the finalization of Chapter 9, which deals with transport policy, despite the fact that 26 other EU member states are ready to approve it. This chapter is one of 33 required reform areas, and while half have already been closed, the remaining ones are critical for Montenegro to meet its self-imposed deadline of joining the bloc in 2028. That date carries significant political weight, serving as a litmus test for the EU’s credibility in expanding eastward and stabilizing the Western Balkans.

The Leverage of the Acquis

Croatia’s blockade is not technically about transport rules. Instead, Zagreb is leveraging the unanimity rule of EU accession negotiations, where every member state must agree to close each chapter, to pressure Montenegro into resolving long-standing bilateral issues. These include the location of 14 people missing since the Croatian War of Independence (1991–1995) and the delimitation of the maritime border between the two Adriatic neighbors.

“A member state is seizing an opportunity to settle old scores using completely legitimate means, the acquis, and they have a limited time to do that,” said a Montenegrin official, speaking on condition of anonymity. The official noted that while the demands are framed as technical or legal necessities, they are deeply rooted in historical trauma and political leverage. “It’s in our interest to work with them because we want to remove all obstacles,” the official added, acknowledging the delicate diplomatic dance required to keep the accession train on track.

Maida Gorčević, Montenegro’s Minister of European Affairs, struck a more optimistic tone, emphasizing ongoing dialogue. “It is a process that is ongoing. Some of these things you cannot resolve overnight,” she told Euractiv. “But the good thing is we have constant communication between the ministries of foreign affairs and a lot of committees which are working on all these questions. I don’t see that Croatia is going to block us, because they haven’t done it so far.”

Foreign Policy and Judicial Chapters

The transport chapter is not the only hurdle. Croatia has also long blocked progress on Chapter 31 (Foreign, Security, and Defense Policy) and Chapter 23 (Judiciary and Fundamental Rights), citing similar bilateral and historical concerns. The tension was recently exacerbated by the funeral of Ratko Mladić, the Bosnian Serb war criminal convicted of genocide in Srebrenica, in Belgrade last month.

The event sparked outrage across the region, particularly when the Speaker of the Montenegrin Parliament sent condolences to Mladić’s family. In the European Parliament, Croatian MEP Sunčana Glavak seized on the incident to question Montenegro’s commitment to EU values. She asked Minister Gorčević whether the speaker’s gesture reflected the government’s position, implying that such actions were incompatible with the democratic standards required for membership.

Gorčević firmly distanced the government from the speaker’s actions. “We do not support the speaker’s move,” she stated, pointing to multiple parliamentary resolutions condemning the Srebrenica genocide. “This is also the position of the political parties and the political environment,” she added, noting her own background as a member of Montenegro’s Bosnian minority to underscore the government’s stance against revisionism.

A Test for EU Enlargement Policy

The dispute has drawn attention from Brussels, with EU Enlargement Commissioner Marta Kos recently calling on Croatia to “settle remaining bilateral issues” ahead of Montenegro’s accession. However, the EU’s hands are tied by the unanimity rule, which allows any single member state to halt the entire process.

Marjan Šarec, a centrist Slovenian MEP and former prime minister, warned against letting bilateral squabbles derail the broader strategic goal of integration. “I hope Montenegro won’t become a victim of bilateral issues,” he said during a recent event in Brussels.

For Croatia, the stance is framed as a matter of principle and justice. A spokesman for the Croatian government stated: “Montenegro is well aware of Croatia’s expectations regarding other outstanding issues of overarching nature, which need to be resolved in a good-neighbourly spirit. The resolution of these issues is long overdue.”

2028 Deadline at Risk

Montenegro’s ambition to join the EU by 2028 is not just a national goal; it is a symbolic benchmark for the EU’s willingness to integrate the Western Balkans. If Croatia’s vetoes persist, they could delay Montenegro’s accession well beyond that date, undermining confidence in the enlargement process and potentially fueling instability in a region still grappling with the legacy of the 1990s conflicts.

As negotiations continue, the ball remains in Zagreb’s court. While Montenegro seeks to address the missing persons issue and border disputes through diplomatic channels, the clock is ticking. For the EU, the challenge is to balance the legitimate grievances of member states with the strategic imperative of bringing stability and democracy to its southeastern flank. Without a breakthrough, the promise of 2028 may remain just another unmet deadline in the long and fraught history of Balkan integration.