Joint training and institutional contacts are already established, and the potential expansion of the trilateral mechanism to Podgorica could significantly alter the security map of the Western Balkans.
The trilateral military-defense mechanism established by Croatia, Albania, and Pristina through the signing of the Joint Declaration on Defense Cooperation on March 18, 2025, could gain a fourth member, Montenegro, in its next phase. Contacts regarding potential expansion already exist, and the entire process is viewed as a long-term endeavor requiring the prior creation of political, security, and social prerequisites.
Although there is no publicly released document or official decision by the Government of Montenegro regarding accession to this declaration, the existing regional military architecture shows that contacts, joint training, and institutional cooperation among all actors have long been established.
The declaration signed on March 18, 2025, envisioned strengthening military interoperability, joint training and exercises, defense industry cooperation, information exchange, and coordination in addressing hybrid threats. During 2026, cooperation transitioned from the ministerial level to the operational military level.
In January 2026, a meeting of directors for defense policy and armaments was held in Zagreb, and in February, the chiefs of general staff of Albania and Croatia met with the commander of the Kosovo Security Force in Shkodër. On that occasion, the preparation of concrete trilateral military exercises was agreed upon. In April 2026, the Croatian Ministry of Defense publicly announced that Zagreb and Tirana wish to continue enhancing trilateral cooperation.
Although Montenegro is not formally part of this trilateral mechanism, it is already present in a number of parallel structures involving the same actors. Particularly significant is the U.S.-Adriatic Charter (A5), whose members are the United States, Croatia, Albania, Montenegro, North Macedonia, and Bosnia and Herzegovina, with Pristina participating as an observer.
Croatia chaired this initiative during 2026, and among the priorities of its chairmanship were joint training, regional resilience, and civil-military cooperation. In March 2026, a representative of Montenegro's Ministry of Defense participated in a meeting of A5 political directors in Croatia, where discussions covered regional resilience, hybrid threats, and civil-military cooperation.
Already in April 2026, under Croatian chairmanship, representatives of the armed forces of Croatia, Albania, and Montenegro, along with representatives from Pristina as observers, were hosted in Zagreb and Udbina. In June 2026, members of the same structures also participated in the international cyber military exercise "Combined Adriatic Cyber Endeavour 2026."
The biggest obstacle to potential expansion is not military-technical but political in nature. Montenegro is a country where a large part of the population identifies nationally as Serbian, the Serbian Orthodox Church (SPC) enjoys great trust among the people, and Serbia is seen as the closest country in the region by the majority of citizens.
An open justification of new military ties with Zagreb, Tirana, and Pristina as a mechanism to respond to the so-called threat from Belgrade would face serious resistance. Therefore, political preparation would have to precede any formal move. According to sources close to regional security processes, a narrative about alleged malign Serbian interference and the need to protect Montenegrin institutions from Belgrade has been built for years within parts of the political, media, and NGO sectors in Montenegro, creating a political foundation on which a future arrangement could be presented as strengthening regional security and good neighborly relations, rather than as turning against Serbia.
A particularly sensitive issue will be the behavior of parties and politicians who entered Montenegrin government thanks to a significant number of Serbian votes. Their support, tacit consent, or lack of resistance would carry far greater political weight than the support of parties that have for years openly advocated NATO and an anti-Serbian political narrative.
What could hardly be sold to the Serbian electorate as an open alignment with a military axis involving Pristina might be presented in more acceptable terms: as enhancing good neighborly relations, fulfilling NATO obligations, or contributing to peace and stability.
An even more sensitive dimension concerns the Serbian Orthodox Church. Sources familiar with the situation indicate the existence of circles within church structures in Montenegro advocating for as much distance as possible from Belgrade and the top of the SPC. Political distancing of Montenegro from Serbia would be far more difficult to implement if there were simultaneously complete church unity and a strong bond between the faithful and the Patriarchate in Belgrade. Therefore, for a lasting change in social perception, various authorities would need to be engaged, including those with influence in religious life.
According to assessments from interlocutors familiar with regional security processes, the initiative for deeper integration of Podgorica with the Zagreb-Tirana-Pristina triangle is not exclusively a regional project. Certain Western political and security structures are also interested in creating a more compact security space in the Adriatic and the Western Balkans.
Montenegro geographically closes the Adriatic space between Albania and Croatia, is a NATO member, is already part of A5 and other regional defense structures, and its military has been developing interoperability with allied forces for years. Former Albanian Defense Minister Piro Vengu publicly stated as early as December 2025 that he sees Pristina's membership in A5 as a strategic necessity.
The key question remains whether the trilateral mechanism will remain with three signatories or expand. As long as a large part of Montenegro's citizens see Serbia as the closest country rather than a security threat, any open alignment of Podgorica with the military-political triangle of Zagreb-Tirana-Pristina would carry a high domestic political risk.
