The Albania-Croatia-Kosovo Trilateral Defence Alliance
Anna Toso | 4 April 2025
Summary
Albania, Croatia, and Kosovo created an alliance to strengthen their defence capabilities and integration to improve the Balkans’ regional security.
The alliance highlights its signatories’ strategic defence investment plans, generating firm opposition from Serbia.
Serbia’s counter-alliance with Hungary and escalating regional tensions will likely increase polarisation in the Balkans, with negative social repercussions, especially at the fragile Kosovo-Serbia border.
Albania, Croatia, and Kosovo signed a declaration for military cooperation on 18 March 2025. The 3 countries committed to jointly working towards stronger integration of their defence strategies and systems. To pursue security and peace in a context of escalating insecurity in Southeastern Europe and the globe, the trilateral agreement sets 4 shared priorities. The goals include developing military capabilities with industrial co-investment, achieving forces interoperability, mitigating hybrid threats risk through shared intelligence, and promoting Kosovo’s integration in the NATO defence ecosystem. The alliance remains open to expanding beyond the Western Balkans, with Bulgaria already mentioned as a potential additional member.
Kosovo's involvement in the alliance triggered strong criticism from Serbia, as the latter does not recognise Kosovo's independence. Serbian Foreign Minister Marko Djuric denounced the agreement as illegitimate and “poses a security threat to the Serbian people and the entire region.” Meanwhile, Serbian President Aleksandar Vučić blamed Albania and Croatia for escalating a regional “arms race” and required justifications for their participation in the agreement. These declarations highlight deteriorating relations and increasing regional tensions in the Western Balkans. Moreover, Djuric accused this alliance of violating the 1996 Agreement on Sub-Regional Arms Control, which limits the armament possession of Serbia, Croatia, Montenegro, and Bosnia and Herzegovina (BiH) after the Bosnian War in 1995. While the Agreement is legally binding, the recent tri-state alliance consists of a non-binding political document defining shared intentions between the signatories.
Such political commitments will have operational consequences. The novel defence alliance will require increased military capacity, equipment, and training. In the short term, the local defence industry cannot meet the augmented demand. The Balkan states already rely on foreign providers. For example, in 2024, Kosovo, Albania, and North Macedonia signed a 5-year-long agreement with Turkey to supply military training, intelligence, logistics, and equipment. Similarly, in December 2024, a Turkish state-owned business supported an ammunition factory’s operationalisation in Kosovo. More broadly, the security alliance highlights Kosovo’s priority in developing its defence industry. Its government plans to gradually transform the Kosovo Security Forces – now lightly armed and exclusively deployable for civil defence purposes – into a formal professional army by 2028.
Strategically, collaborating with Albania and Croatia implies that Kosovo can indirectly access NATO and the European Union (EU) resources despite not being a member. Specifically, being an EU Member State (MS), Croatia will benefit from the ReArm Europe/Readiness 2030 programme. The EU Commission plans to allocate EUR 800b (USD 866b) to support its MSs’ investments to strengthen their domestic defence industry. The Balkan alliance and the EU strategy promote interoperability and cross-border cooperation while spurring private and public investment in defence. Both comply with the worldwide trend of soaring expenditure on re-armament, which registers year-over-year growth rates in acceleration – 7.4% in 2024, compared to 6.5% in 2023 and 3.5% in 2022.
Lastly, the defence agreement prompted Serbia to work on a counter-alliance with Hungary, giving up its traditional neutrality. Given the Hungarian pro-Russia stance, the Serbia-Hungary cooperation, formalised on 1 April 2025, contrasts the interests of the pro-NATO Albania-Croatia-Kosovo alliance, exacerbating geopolitical polarisation and social tensions in the Balkans. Internationally, Serbia’s cooperative relationship with NATO, based on the 2015 Individual Partnership Action Plan, would also deteriorate. Heightened polarisation in the Balkans could fuel the secessionist tendencies of the Serbia-backed Republica Serbska (RS). RS leader Milorad Dodik has recently been condemned for attempting to secede from the tri-partite system governing BiH since 1995. Nonetheless, the RS national assembly has drafted laws establishing an autonomous army, judiciary, and constitution.
Forecast
Medium-term (3-12 months)
There is a realistic possibility that more Balkan countries will join the new Western Balkan tripartite alliance.
The escalating tensions and the tit-for-tat political and diplomatic behaviours will likely increase the risk of social clashes in the region, especially at the border between Serbia and Kosovo, where peace is already fragile.
Long-term (>1 year)
The Balkans’ long-term security trajectory is unlikely to achieve regional cohesion soon. Given that Serbia and Hungary formalised the defence counter-alliance, the relations between Serbia and its neighbours will almost certainly become tenser in the coming years.
Improving inclusion and transparency among regional stakeholders, including Serbia, in future dialogues about regional security would be key to creating a realistic possibility of preventing further escalation of enmities in the Balkans.
