Military Build-up in the Western Balkans Raises Regional Security Concerns

Europe’s most fragile region is undergoing a quiet recalibration towards increased military preparedness, driven by shifting power dynamics and growing trans-Atlantic tensions. While not signaling imminent war, the Western Balkans is experiencing a complex environment shaped by uneven military capabilities, alliance asymmetries, and competing political narratives. This modernization isn’t simply technical upgrades; it represents a significant shift in the regional balance of power.

A Postwar Balkans in Transition

Following the ethnic wars of the 1990s, the Balkans initially focused on disarmament and externally guaranteed peace. However, unresolved ethno-territorial disputes continue to shape security perceptions. Serbia’s non-recognition of Kosovo’s independence and the internal fragmentation of Bosnia and Herzegovina under the Dayton framework remain key sources of tension. These lingering issues mean even defensive military development is often viewed through the lens of past conflicts rather than purely technical advancement. [1]

Serbia Leads the Way in Military Modernization

Serbia initiated a significant military modernization process around 2015, largely unnoticed by outside observers until 2020. [1] Its defense budget now exceeds $2 billion annually, representing roughly 2.5% of its GDP. [1] This buildup includes investments in combat aircraft, air defense systems, armored vehicles, drones, and electronic warfare capabilities. Serbia frames this modernization as a response to perceived strategic constraints, including NATO expansion and the presence of NATO forces in Kosovo and Bosnia and Herzegovina. [1]

Serbia’s procurement strategy is notable for its diversification, acquiring technologies from Israel, France, Russia, and China. This contrasts with NATO members, whose modernization is largely guided by alliance interoperability requirements. [1] In September 2023, an incident involving heavily armed men crossing into northern Kosovo, resulting in the death of a police officer and the discovery of Serbian-sourced weaponry, highlighted the potential for escalation. [1]

Neighboring States Respond

Serbia’s military buildup has prompted responses from neighboring countries:

• Albania: Accelerated efforts to meet NATO capability benchmarks, focusing on air defense and artillery modernization.
• Croatia: Modernized within the NATO framework, acquiring Rafale fighters, Bradley infantry vehicles, and Leopard 2 tanks.
• Montenegro & North Macedonia: Focused on resilience and interoperability within NATO, investing in rapid reaction forces and enhanced surveillance capabilities.
• Kosovo: Expanded its Security Force, prioritizing a credible deterrent capable of rapid response, considering Serbia’s military superiority.
• Bosnia and Herzegovina: Increased defense spending incrementally, prioritizing readiness and NATO interoperability where feasible.

The Role of Defense Industries and External Influence

National defense industries are re-emerging in the region, with Serbia’s Yugoimport SDPR and Croatia’s industry playing key roles. [1] External powers, including Russia, China, Turkey, and Gulf states, are also increasing their influence through arms sales and advisory services. [1]

Policy Implications and the Path Forward

While the current arms race reflects preparation rather than panic, a politics of restraint is crucial to prevent miscalculation and escalation. Confidence-building measures, such as expanded military-to-military communication and transparency in procurement plans, are essential. [1] Normalization of relations between Serbia and Kosovo remains a key priority for long-term regional stability. [1]

Europe and the United States must maintain a clear understanding of Balkan military developments and how imbalances could affect stability. Accountability requires adherence to alliance standards for NATO members, transparency obligations for non-members, and restraint in political and military signaling across the region. [1] Without these guardrails, modernization risks reinforcing insecurity rather than deterrence.

The Western Balkans, defined geographically as a region in Southeastern Europe, encompassing countries like Albania, Bosnia and Herzegovina, Croatia, Kosovo, Montenegro, North Macedonia, and Serbia, [2] will maintain stability only under disciplined transparency and measured military modernization.