Emerging military alliances in the Western Balkans: A redrawing of the regional security map

On 18 March 2025, Ministers of Defence from Albania, Croatia, and Kosovo gathered in Tirana, Albania, to sign a trilateral security and defence agreement, an initiative that, while unsurprising to seasoned regional observers, introduced a new layer to an already complex strategic environment.

This agreement marked a new twist in the already complex security environment in place in the Western Balkans since the end of the conflicts of the 1990s. The fruits of the Tirana gathering quickly triggered a reaction in the wider neighbourhood – namely in Serbia and Hungary, with the announcement of another, competing sub-regional alliance. Yet what are these new alliances intending to achieve, given that some of the signatories are full NATO (and EU) members and others are seeking membership of such organisations in the future? Are they merely examples of small states posturing, asserting the importance of sovereignty, while vying for greater influence in a region still feeling the consequences of the wars of the 1990 – less Realpolitik and more Real Theatre? Are these moves simply an extension of a desire for greater recognition in the wider neighbourhood and in the context of all eyes on Ukraine? Or are they simply examples of regional strongmen looking to further their international credentials when all is not well at home on the domestic front?

This article examines the context and possible reasons behind these new regional alliances. Perhaps the most surprising is the case of Albania and Croatia joining up in this way, since both are full NATO members. Reflecting the complex and ever shifting geopolitical dynamics of the region, the article also looks at the wider impact in the region, which continues to balance competing influences at play, mainly from Brussels and Moscow.

The Adriatic Bloc, closer alignment

The Tirana Declaration brings Albania, Croatia, and Kosovo closer together in a joint defence and security framework, formalising what has in practice been years of close coordination. In some ways, this new sub-regional alliance can be viewed solely through the lens of closer military cooperation among NATO-aligned states from the region.

In this regard, the Tirana Declaration includes a number of ambitious goals:

• Development of defence technologies and infrastructure
• Interoperability through education and coordinated training
• Joint procurement
• Combatting hybrid threats (cyber and disinformation)
• Promotion of Kosovo’s Euro-Atlantic integration, including NATO membership

Tirana takeaways

While many of these elements already exist in bilateral form, the declaration frames them under a single strategic architecture aligned with NATO’s Strategic Concept and the EU’s Strategic Compass. In doing so, the bloc positions itself as a credible contributor to the Euro-Atlantic security, thereby cementing their Euro-Atlantic credentials.

The new alliance members have pledged to promote their defence capabilities and industrial cooperation, having agreed to seek opportunities in procurement especially, with the principal aim being the improvement of their respective state of readiness.

Concrete steps will be undertaken to enhance interoperability through education, training, and joint exercises: in this regard, the Tirana Declaration outlines the intention to exchange expertise and share best practices in areas such as recruitment, personnel development, and staff/personnel retention. It also emphasises the goal of improving individual and collective educational and training opportunities through respective military academies and institutions.

In order to more effectively combat growing hybrid threats and strengthen the collective resilience of their armed forces overall, the three signatories will examine response options to a broad range of potential threats to critical infrastructure and communication networks.

No issue looms larger in the Western Balkan region than Kosovo.^[1] Its independence, declared in 2008, remains unrecognised by Serbia and several EU members, along with two UN Security Council permanent members – China and Russia. For Albania and Croatia, supporting Kosovo’s NATO accession is both a strategic, ideological and moral imperative. For Belgrade, and the vast majority of Serbian citizens, it well and truly remains a red line.

The inclusion of Kosovo in the Tirana agreement triggered outrage in Belgrade. Serbian officials accused the alliance of “destabilising the region” and vowed to counteract any attempt to militarise Kosovo’s security forces. Yet Kosovo’s presence also illustrates how the alliances are shaping regional identities. Where once the question was, ‘Should Kosovo be part of the Balkans’ security future?’ the new framing is, ‘Who will help shape that future—and on whose terms?’

While supporting Kosovo’s Euro-Atlantic integration path, the Declaration includes closer cooperation and coordination for the full integration of Kosovo into regional security and defence initiatives, beginning with its joining NATO’s Partnership for Peace (PfP) programme. However, Kosovo’s accession to PfP faces challenges, notably the non-recognition of its independence by four NATO members: NATO has maintained a peacekeeping presence in Kosovo through the Kosovo Force (KFOR) since 1999. As of March 2025, KFOR comprises 4,686 troops from 27 nations, underscoring NATO’s commitment to stability in the region.

Perhaps what is most striking about this trilateral alliance and what sets it apart from other agreement of its kind in the region, is its unambiguous framing as a response to “emerging security challenges” in the region — a thinly veiled reference to increasing Russian influence and past regional tensions, particularly with Serbia. In this vein, Albania’s longest-serving, four-term Socialist Prime Minister Edi Rama stated at the summit that “The Western Balkans has no time for ambiguity,” before adding that “We are either in the tent of collective security, or we are alone with our vulnerabilities.”

In fact, Tirana has significantly upgraded its military infrastructure in recent years, primarily thanks to NATO support, including through the impressive modernisation of its airbases in Kuçovë and Farka. In Kuçovë alone, USD 50 million has been spent by NATO on transforming the base into a major regional air hub for NATO’s air forces.

For its part, Croatia, one of NATO’s more advanced regional members, has pressed ahead with UAV integration and joint maritime patrols with Albania. While not a NATO member, Kosovo receives logistical and advisory support from the NATO Alliance as it seeks to bolster its security and defence capabilities.

In short, the Adriatic Bloc is not just symbolic; there’s certainly more to this arrangement than meets the eye. While it reflects practical and material cooperation, coordinated defence postures, and a clear alignment with NATO goals, its creation has expectedly prompted concern among non-aligned neighbours, chief among them, Serbia. Thus far, North Macedonia, although a NATO member since 2020, has chosen not to join any of the new alliances, though is largely aligned to the goals and strategic aims of the Adriatic Bloc given its NATO membership.

Serbia pushes back – with a like-minded neighbour

Just two weeks after the signing of the Tirana Declaration, on 1 April 2025 in Subotica, in the northern province of Vojvodina, Serbia, President Aleksandar Vučić met his Hungarian counterpart, Prime Minister Viktor Orbán – both regional hardliners – to sign their own bilateral military cooperation agreement. The timing, location, and symbolism leave little to interpretation. While presented as routine coordination between like-minded (and pro-Russian) neighbours, the Subotica agreement was clearly designed as a countermeasure to the NATO-aligned Adriatic bloc.

Belgrade’s nervousness with any NATO-aligned activity on its southern borders comes as no surprise. The 1999 NATO bombing campaign during the Kosovo War remains a neuralgic scar in Serbia’s recent memory, and though Serbia has participated in various NATO PfP programmes, it has thus far not pursued full membership status.

So, in a move few observers saw coming, Belgrade responded to the Tirana Declaration by signing a defence cooperation agreement with Hungary. Bearing some similarities to the freshly inked Tirana document, this agreement includes: Joint military exercises and exchange of intelligence; support for domestic defence industries; and long-term cooperation on critical infrastructure and border security.

Both Vučić and Orbán have stated publicly that their mini-Alliance should not be seen as an anti-NATO bloc, though very few observers believe the timing is coincidental. Serbia’s military has traditionally relied on a mix of domestic and Russian hardware (a legacy of the Yugoslav Army, which Serbia inherited), and even though the Serbian Armed Forces’ procurement picture is beginning to show signs of diversification, Belgrade continues to be sceptical regarding NATO’s real intentions in the region.

This development is all the more absorbing due to the possible inclusion of another like-minded neighbour, Slovakia. While Slovakia has not formally joined the Serbia-Hungary alliance, some Serbian members of parliament have suggested that talks are underway. The inclusion of Slovakia would not come as a surprise, given that Slovakia’s Prime Minister Robert Fico shares the same pro-Russian sentiments of Vučić and Orban. The country enjoys a close historical, cultural and political relationship with both countries, and Fico has begun to share his concern about the perceived marginalisation of Central European voices within the wider EU defence framework.

Old tensions resurfacing…

In this region of Europe, arguably more so than others, historical context counts; and the Balkans has never lent itself to a clean and simple security architecture. Beyond the scope of this article, but suffice it to say, the Balkans has witnessed its fair share of geopolitical strife and conflict between competing Empires – Austro-Hungarian and Ottoman chief among them. During the height of Josip Broz Tito’s foreign policy successes, Yugoslavia enjoyed its time in the sun, as one of the leading lights of the Cold War-era non-aligned movement, together with Nasser’s Egypt and Nehru’s India. While the post-Yugoslav era saw EU and NATO enlargement as stabilising forces—this has not been the case for all.

Slovenia and Croatia were two of the former Yugoslav Republics that quickly embraced this strategic path, with Albania, Montenegro, and North Macedonia following later. While Kosovo remains stuck in limbo, Serbia has chosen strategic ambiguity, balancing its economic cooperation with the EU, while nurturing a defence and security relationship with both Russia and China.

These two new alliances certainly don’t represent a return to Cold War-era politics, but they do show an already fractious region dividing once more into competing orbits. While the Adriatic bloc is firmly embedded in the Euro-Atlantic project, the Serbia–Hungary alliance represents something more uncertain, favouring a future where sovereignty is chosen over integration, and tradition rules over transformation.

External influence – familiar suspects

These shifts are not happening in isolation. The United States remains a key enabler of NATO infrastructure and capability-building across the region, particularly in Albania and North Macedonia. Washington has reiterated its support for Kosovo’s integration into NATO structures and continues to sponsor regional interoperability initiatives.

The EU, by contrast remains cautious, as can be expected. While supportive of regional cooperation in principle, Brussels has shown concern over self-assembled blocs that could compete with its enlargement agenda or dilute the cohesion of its Common Security and Defence Policy (CSDP).

Russia has predictably sided with and praised Serbia’s stance, while condemning NATO’s “provocation” in the form of the Tirana pact. China, for its part has been slowly and steadily expanding its economic influence and infrastructure footprint in Serbia, signalling its long-term strategic interest.

Alliances to stay – or a fleeting Balkan moment?

Observers caution that neither of the two new alliances are built to last in the long run, not least as defence budgets across the continent are stretched, and none more so than in the Balkans. Moreover, NATO members Albania and Croatia have the Alliance’s higher defence spending quota to meet above all.

So, what are we seeing? A turning point—or just another Balkan flash in the pan? To dismiss these new alliances as mere theatre misses the point, since they are more than just about arms and strategic choices — they are essentially all about signalling and identity, when all eyes for some time have been on Ukraine and almost nowhere else (a situation which doesn’t look likely to change any time soon). It is also all about who is moving decisively enough and quickly enough to shape the regional order.

In short, these alliances reveal real concerns about security and influence in the region and in the case of Hungary and Serbia, are all about sovereignty. Yet they have also been created to bolster leaders at home – most notably with Serbia’s Vučić, faced with months of student-led protests and a restless general public, now with many calling for early elections – though Orbán has also begun to experience an invigorated opposition movement at home.

What is certain is that the Western Balkans is no longer static when it comes to security and defence arrangements and allegiances. As new lines are being drawn—through pacts, platforms, and partnerships—what comes next may shape the region’s security for a generation.

Lincoln Gardner

[1] Over 110 countries have recognised Kosovo’s independence, including the US and most EU member states (minus Greece, Romania, Slovakia, and Spain).