NATO-KFOR’s Deterrence in Northern Kosovo

NATO-KFOR’s Deterrence in Northern Kosovo: A Strategic Reassessment after Banjska

Diar Bala

This report briefly examines NATO-KFOR’s peacekeeping role in Kosovo and its success in helping shape a post-war society and tackling Kosovo’s state-building challenges. It also assesses NATO-KFOR as an effective peacekeeping instrument within its limits, while arguing that NATO-KFOR either needs reform to better address the ongoing threats facing Kosovo and its institutions or should begin a transition to the Kosovo Security Forces (KSF).

The Kosovo Force (KFOR) is a NATO-led peacekeeping force and the third security responder in Kosovo. KFOR, under the NATO umbrella and authorised by United Nations Security Council Resolution (UNSCR) 1244, entered Kosovo on June 12, 1999 (KFOR, 2025) at a time when its population was facing a grave humanitarian crisis. NATO-KFOR’s objectives in Kosovo are primarily security-focused, aiming to deter and prevent renewed hostilities and to establish a safe and secure environment as well as freedom of movement for all citizens of Kosovo (NATO, 2018). NATO-KFOR is widely regarded as one of the more successful peacekeeping missions to date and has maintained relative stability and peace in Kosovo. As the third security responder in Kosovo, KFOR has maintained the hard-won peace to a relatively strong degree, responding swiftly to security incidents, ensuring freedom of movement for all citizens, and working closely with the European Union Rule of Law Mission in Kosovo (EULEX) and the Kosovo Police (KP). However, the NATO-KFOR mission has come under scrutiny since 2022 for not deterring and preventing Serbian aggression towards Kosovo, which has destabilised the wider region and has led to the injury of many KFOR personnel serving in Kosovo (Koha, 2025). Therefore, this report will argue that while KFOR has done well to maintain a relative degree of peace and stability in Kosovo, it requires serious reform to equip itself better to address the threats it faces or to initiate a transition to the KSF, which will be primarily responsible for responding to security events in Kosovo.

Contextual Background:

Historical accounts suggest that the inhabitants of Kosovo were Albanian when Serbia annexed it in 1912 (Ceku, 2024). Serbian claims over Kosovo date back to the thirteenth century, with the establishment of the Serbian Orthodox Church (SOC) in Kosovo, the subsequent Battle of Kosovo in 1389, and the defeat of the Serbs against the Ottoman Empire. Between 1912 and 1914, Montenegro expropriated 55,000 hectares of Albanian land and transferred it to 5,000 Montenegrin settlers (Malcolm, 1998, p. 53). Kosovo then became a part of Yugoslavia in 1929. After WW2, the Socialist Federal Republic of Yugoslavia (SFRY) was established with Josip Broz Tito as its head, who ruled until he died in 1980. Kosovo’s status was an ‘autonomous province’ within Serbia until the 1974 Yugoslav Constitution upgraded its status to a de facto constituent Republic, enjoying almost equal rights. In 1986, Slobodan Milosevic, regarded as the architect of the wars of the 1990s, became the President of the Serbian Communist Party. In 1989, Milosevic rose to become the President of the state Presidency of Serbia 1989 and in 1990, the Serbian Government revoked Kosovo’s autonomy, which it had received under the 1974 Yugoslav Constitution. In response, the Albanian deputies of the Provincial Assembly, which had been dissolved in 1989 by the Serbian government, met underground and declared the ‘Republic of Kosova’ a sovereign and independent state on 22 September 1991, where over 99% of voters and

114/123 Albanian deputies voted in favour of independence with a turnout of 87%. The Serbian Government continued to rescind the rights of the Kosovo Albanians and sought to return Kosovo’s status to 1912, when it was annexed by Serbia. Resistance began in the 1990s, with Kosovo Albanians converting private homes and facilities into universities and medical institutions. While many were fired from their workplaces and replaced by Serbs, a united society began to form and metastasise until 1997, when this passive resistance was eventually replaced with an armed one. The Kosovo Liberation Army (KLA) began conducting small-scale organised attacks against Serbian military and police assets in Kosovo, declaring its intention to achieve independence from Serbia. Serbia’s crackdown was disproportionate, immediate and brutal. From 1998-99, Serbian paramilitary and military forces were responsible for massacres, indiscriminate killings and the displacement of over 800,000 Kosovo Albanians in what was regarded as a systemic ethnic cleansing campaign directly authorised by Milosevic. The conflict ended after a 78-day aerial bombing campaign launched by NATO on 24 March

1999, which saw Serbian forces withdrawing from Kosovo in June 1999 and the subsequent deployment of KFOR on the ground. KFOR was authorised by UNSC Resolution 1244 and initially comprised 50,000 strong. Kosovo was placed under the temporary administration of the United Nations Mission in Kosovo (UNMIK) from June 1999 to February 2008. On 17 February 2008, Kosovo declared its independence and was recognised immediately by the US, the UK, and many other Western partners. On 22 July 2010, the International Court of Justice (ICJ) issued its advisory opinion on Kosovo, declaring that Kosovo’s unilateral declaration of independence was not in breach of international law, reaffirming Kosovo’s independence. Today, over 121 countries recognise the Republic of Kosovo's independence.

North Kosovo as a Significant Flashpoint:

The North of Kosovo, which comprises four Serb-majority municipalities of Leposavić, North Mitrovica, Zubin Potok and Zvečan, is home to nearly half of Kosovo’s Serb minority with a total population of 50,000, where 90% of this are Serb inhabitants and the rest Albanian. These four municipalities, or ‘the North’, are included as part of Kosovo’s internationally recognised borders; they were under Serbian control for pretty much a quarter of a century. The North has operated under a system of dual sovereignty, maintained at an uneasy equilibrium between Serbia and Kosovo, and each municipality has two official websites, one for each system. Residents can get both Kosovo and Serbian personal documents (Crisis Group, 2024). While this system of dual sovereignty maintained the peace to a certain extent for 25 years, Pristina became determined to reassert Kosovo’s sovereignty over the four municipalities and close Serbia’s foothold in the North.

Since 2021, the government, led by Prime Minister Albin Kurti, has dismantled Serbian-run structures in the North. Starting in 2021, a dispute over license plates arose, with Kurti demanding that Serb residents change their plates when entering Kosovo. Serbs protested, barricades were erected, and police were deployed to control protests. Following EU-US mediation, the police withdrew, and a compromise was reached that allowed citizens to cross with stickers on their plates. Kosovo then targeted smuggling routes, resulting in resistance and injuries in July 2022. Currently, Pristina claims no illegal Serb structures remain (Svecla 2025: AP News, 2025). However, after the dismissal of police commander Nenad Djuric for refusing to enforce measures against Serbian plates, Northern Serbs resigned from government roles in

November (International Crisis Group, 2023), including all four Serb mayors and 10 Serbian MPs. Following local elections in April 2023, 4 Albanian mayors were elected amid low turnout due to Kosovo Serb boycotts. The QUINT, including France, Germany, Italy, the UK, and the U.S, condemned these elections and urged Pristina to reintegrate Kosovo Serbs. On May 29, a mob of Serbian protesters clashed with KFOR, throwing rocks and explosives at the NATO cordon and the Albanian mayors. Protesters demanded the withdrawal of Kosovo Police Special Forces and the resignation of elected Albanian officials. Reportedly, over 90 KFOR soldiers were injured, with 2 Hungarians requiring leg amputations, after Serbian mob attacks (Reuters, 2024). PM Kurti’s Kosovo government maintained authority over the North despite EU-US pressure.

The Banjska Attack:

The most serious escalation in Kosovo-Serbia tensions occurred in September 2023 when a clash between Kosovo’s forces and Serb paramilitaries resulted in four deaths, including one Kosovo Police Sergeant and three Serbian gunmen. Approximately 90 heavily armed Serb gunmen and fighters infiltrated northern Kosovo, killing a Kosovo Police Sergeant, with an anti-personnel remote-controlled mine (Ministry of Foreign Affairs & Diaspora, 2023; Helsinki Committee for Human Rights, 2025). Kosovo Special Police and Military Units were deployed. At the same time, the Serb militia barricaded themselves inside an Orthodox Monastery in an apparent attempt to frame the Kosovo Police as aggressors against Serb heritage in northern Kosovo, seemingly aiming to depict the Serbs of Kosovo as a persecuted minority (UNMIK Media Observer, 2023). The Kosovo Government released footage showing Milan Radoicic, Vice-President of the Serbian List political party, leading the armed militia in attacks on the Kosovo Police (Radio Free Europe, 2023).

An official report released by the Kosovo Ministry of Foreign Affairs and Diaspora describes this in more detail: ‘The location of the Monastery and the way the operation was planned and executed leaves no doubt that calculating fatalities in the course of a police operation against the terrorists at a monastery of the Serbian Orthodox Church in Kosova, were meant to contribute to the pretext for a military intervention to allegedly save endangered Serbian citizens of Kosova and pilgrims from Serbia’

Figure 1: 1: Guesthouse, where the first paramilitary group settled. 2: Drone footage from the same location showing Milan Radoicic, VP of the Srpska Lista Party. 3,4: Thermal drone footage showing several paramilitaries in two marked areas.

Figure 2: 1: Roadblock set up on the bridge with trucks: Paramilitary hiding with a 'Zolja’ grenade launcher. 2,3: Vehicles of the attacked KP teams.

Analysis:

KFOR’s failure to serve as an effective tool for both interstate and intrastate deterrence highlights the urgent need to either adapt to the rapidly evolving security situation in Kosovo or initiate a transition process whereby the KSF becomes the primary guarantor of Kosovo’s security. As the third security responder in Kosovo, KFOR cannot effectively deter all threats it encounters or those faced by Kosovo. Nevertheless, it can enhance its capabilities and support the Kosovo Police and the KSF in their operations. KFOR’s inability to prevent the protests during the May 2023 attacks revealed a critical weakness. KFOR was insufficiently prepared to confront attackers and disperse the protesters directly. While KFOR’s role is to prevent inter-ethnic tensions from escalating, it operates within a framework of strategic ambiguity, given the political repercussions that KFOR and Kosovo would face if KFOR were to take decisive action against a particular group. For example, KFOR’s apparent reluctance or fear of using force has serious consequences not only for KFOR itself but also for both Serbs and Albanians residing in Kosovo.

In May 2023, KFOR responded in a purely defensive manner, counterbalancing rather than acting as a peace enforcer, creating the impression that violence against KFOR personnel could occur without consequences, provided there were no critical injuries or fatalities. KFOR’s response to the Serbian mob’s aggression should have been more assertive in May 2023, including arrests, an expanded and reinforced cordon and the display of force using anti-protest equipment or other coercive measures. In June 2023, Ristuccia stated that NATO “plans to face any kind of circumstances” but stressed that “there is no military solution and that the only solution is a political decision to de-escalate tensions,” reflecting KFOR’s strategic ambiguity and political limitations. KFOR’s limited reaction to unprecedented violence in Kosovo since 1999 during the May 2023 events exposed its difficulties in acting as a significant deterrent against Serb aggression. This situation could have been avoided if political conditions had permitted the KSF or KP to respond to the Serbian mob.

The use of military-grade equipment and the coordinated plan to seize control of the Northern Part of Kosovo across 37 locations in September 2023 signified KFOR’s failure to deter the Banjska attack and to act decisively in deterrence. In July 2023, Alicia Kearns MP, then Chairwoman of the UK Foreign Affairs Select Committee, warned about weapons smuggling from Serbia into Kosovo via ambulances and their concealment in Serbian Orthodox Church buildings in the North, publicly urging KFOR to broaden its mandate and address the issue.

KFOR’s response was limited; it dismissed the allegations and reiterated that its mission is to maintain peace rather than enforce authority. However, KFOR’s primary goal remains deterring renewed conflict and safeguarding overall security in Kosovo, which might have been better served by acknowledging the concerns raised by British Parliamentarians two months before the Banjska attack. The responses to the May 2023 assaults on KFOR personnel and the September 2023 Banjska attack seem to operate within a framework of strategic stability rather than a longer-term operational standard—more focused on containment and restoring the status quo rather than adopting a more effective approach, which would require a stronger mandate or transferring responsibility to the KSF.

Policy Recommendations:

Conclusion:

Recent security developments in Kosovo, particularly in the northern part of the country, have revealed the limited effectiveness of once-strong, proven deterrence tools such as KFOR. The nature of the threat to Kosovo has broadened to include non-state actors and other forms of hybrid aggression. At the same time, direct physical assaults remain a possibility – as seen in the Banjska attack. This display of hostility highlights the urgent need for Kosovo’s security framework to evolve and become self-sufficient, ideally through modernising and transforming the KSF into a professional defensive force capable of responding to security incidents across the country and aligned with NATO standards. Although this may seem idealistic given the current political climate and strained relations between Kosovo and Serbia, reviewing KFOR’s mandate could help close the security gap and address some concerns. Alternatively, increased cooperation between KFOR and the KSF could be a feasible measure, provided it is acceptable to Serbia—particularly if the KSF is granted a mandate to protect the Serb minority. KFOR will remain in Kosovo for the foreseeable future, but it must shed political constraints or enable the KSF to develop into a professional force to maintain the hard-won peace and security in Kosovo.

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