Bulgaria’s request on 16 October 2026 for additional fighter aircraft and counter-unmanned aerial vehicle (UAV) defence systems from the North Atlantic Treaty Organization (NATO) has brought renewed attention to the changing security needs on the Alliance’s southeastern flank. Submitted following UAV attacks targeting commercial vessels, the request has once again placed NATO’s collective defence mechanism in the spotlight. The allied reconnaissance support that began on 20 October 2026 and the additional military measures announced by Bulgaria the following day indicate that these security requests are beginning to receive an operational response. Nevertheless, the difference between the active defence capabilities requested by Bulgaria and the surveillance and reconnaissance support provided makes it necessary to assess the Alliance’s capacity to respond to evolving threats.[i]
The background to Bulgaria’s request lies in the security risks posed by UAV activity in and around the country’s airspace in recent months. On 8 August 2026, a UAV that entered Bulgarian airspace from the Romanian border exploded on Bulgarian territory, exposing limitations in existing early-warning capabilities. According to the Bulgarian government, the vehicle was not detected by Bulgarian or Romanian air surveillance systems or by NATO’s Combined Air Operations Centre Torrejon. Although the incident resulted in no casualties or infrastructure damage, the vehicle’s proximity to critical infrastructure facilities heightened security concerns.[ii] The intensification of attacks targeting commercial vessels in October has further reinforced the regional dimension of these risks. Therefore, for Bulgaria, the primary concern is protecting its airspace and ensuring a timely response to potential violations, regardless of the source of the threat.
In this context, Sofia’s request for fighter aircraft, surface-to-air missile systems, and counter-UAV capabilities demonstrates the need for complementary defence assets to address different types of threats. Fighter aircraft are important for monitoring airspace and identifying suspicious objects, while counter-UAV systems can offer more suitable solutions against small, low-flying, and difficult-to-detect vehicles in particular. The use of conventional air defence systems against low-cost UAVs creates limitations in terms of ammunition costs and operational sustainability. Delays in the modernisation of the Bulgarian Air Force further underscore this need. According to information released in August 2026, delivery of the second batch of eight F-16 Block 70 fighter aircraft ordered by Bulgaria could be delayed until 2030. This makes it increasingly important for Bulgaria to continue operating its existing MiG-29 fleet and manage the transition in its air defence capabilities with allied support.[iii] Therefore, Sofia’s request points to the need for a more integrated air defence architecture that extends beyond the pursuit of temporary military support.
NATO’s first concrete support for Bulgaria came in the form of the deployment of a US P-8 Poseidon maritime patrol and reconnaissance aircraft. On 20 October 2026, Bulgarian Prime Minister Rumen Radev confirmed that the aircraft had begun reconnaissance operations to identify potential threats. Defence Minister Dimitar Stoyanov stated that the deployment decision had been made jointly by Bulgaria and NATO and that the information gathered was being shared with the Alliance.[iv] This development was followed by national measures announced by Bulgaria’s Ministry of Defence on 21 October 2026. The ministry reported that F-16, MiG-29, Su-25, and L-39 aircraft had increased their patrol, surveillance, and reconnaissance activities.[v] Bulgaria’s security request has thus begun to take concrete shape through the mobilisation of national military capabilities and the provision of allied support. However, the announced measures do not mean that NATO has fully accepted Bulgaria’s request for the deployment of additional fighter aircraft or counter-UAV systems specifically for the country.
In this context, strengthening radar systems, early-warning capabilities, and counter-UAV systems could contribute to deterrence by denial by reducing the likelihood of successful airspace incursions. This approach is based on lowering a potential adversary’s chances of achieving its military or strategic objectives.[vi]
However, detecting a threat and neutralising it do not produce the same operational outcome. While the reconnaissance capabilities provided by the P-8 Poseidon contribute to identifying potential threats and facilitating information-sharing among allies, they do not offer a direct intervention capability. Bulgaria’s increased air patrols and deployed defence assets, meanwhile, have the potential to complement these capabilities. Effective deterrence therefore depends on the integrated functioning of detection, identification, decision-making, and response processes. The long-term impact of NATO’s support can also be assessed in terms of the extent to which this operational integration is strengthened.
Bulgaria’s initiative is also significant in the context of debates within NATO over security guarantees and burden-sharing. The alliance security dilemma explains the tension between member states’ concerns about being deprived of allied support and the risk of the Alliance being drawn into an unwanted conflict.[vii] Although Bulgaria’s request cannot be interpreted directly as evidence of a fear of abandonment, Sofia’s call for additional military capabilities demonstrates the importance it attaches to underpinning collective defence commitments with tangible capabilities. For NATO, the challenge is to strike a balance between meeting allies’ security expectations and ensuring that military measures do not lead to an escalation of the conflict. The restriction of the P-8 Poseidon’s role to reconnaissance missions, alongside Bulgaria’s mobilisation of its national defence assets, suggests that the Alliance is currently seeking to maintain this balance through surveillance, early warning, and defence preparedness. Nevertheless, continued demands for additional active defence capabilities could bring more comprehensive adjustments to the Alliance’s security assurance policy onto the agenda.
Another dimension of Bulgaria’s security initiative is the potential for operational coordination with Türkiye and Romania. Defence Minister Stoyanov’s statement that he had been in contact with his counterparts in both countries and that a trilateral meeting was expected to establish a common approach indicates that Sofia seeks to address its security needs through regional cooperation.[viii] The existing mine countermeasure cooperation between Türkiye, Romania, and Bulgaria demonstrates that the three countries have experience coordinating efforts to address shared security challenges. However, it should not be assumed that the existing cooperation on maritime security will directly evolve into a joint air defence mechanism. Such a development would require additional arrangements concerning the sharing of threat information, the interoperability of early-warning systems, and the delineation of response authorities. For Türkiye, this process could create an opportunity to contribute to NATO’s defence activities on its southeastern flank and play an active role in regional security coordination.
In conclusion, Bulgaria’s request for additional air defence capabilities from NATO has highlighted the impact of evolving threats on existing defence arrangements along the Alliance’s southeastern flank. The deployment of the P-8 Poseidon and Bulgaria’s increased national military measures indicate that these security requests are beginning to receive a tangible response. However, these developments do not mean that all the defence capabilities requested by Sofia have been provided. In the period ahead, various options may emerge, including the deployment of additional fighter aircraft or counter-UAV systems, the expansion of existing reconnaissance activities, or the enhancement of regional coordination. Each of these options would have different implications for the Alliance’s deterrence capabilities and its member states’ security expectations. The Bulgarian case will serve as an important indicator of NATO’s ability to translate its collective defence commitments into tangible and sustainable capabilities in response to evolving military threats.
[i] “Bulgaria seeks NATO anti-drone systems, says defence minister”, Reuters, https://www.reuters.com/business/aerospace-defense/bulgaria-seeks-nato-anti-drone-systems-says-defence-minister-2026-10-16/, (Date of Access: 17.10.2026).
[ii] “Prime Minister Rumen Radev: Drone invades Bulgarian airspace across Romanian border and explodes without causing casualties and damage”, Council of Ministers of the Republic of Bulgaria, https://www.government.bg/special/en/Press-center/News/Prime-Minister-Rumen-Radev-Drone-invades-Bulgarian-airspace-across-Romanian-border-and-explodes-without-causing-casualties-and-damage, (Date of Access: 17.10.2026).
[iii] “Bulgaria Marks Aviation and Air Force Day, Commander Says Airspace Defence Missions Continue”, Bulgarian News Agency (BTA), https://www.bta.bg/en/news/bulgaria/1226421-bulgaria-marks-aviation-and-air-force-day-commander-says-airspace-defence-missi, (Date of Access: 17.10.2026).
[iv] “US P-8 Poseidon Aircraft Patrols Black Sea Amid Deteriorating Security Environment”, BTA, https://www.bta.bg/en/news/1228518-us-p-8-poseidon-aircraft-patrols-black-sea-amid-deteriorating-security-environme, (Date of Access: 21.10.2026).
[v] “Defence Minister: Bulgarian aviation activity along Black Sea coast being stepped up”, The Sofia Globe, https://sofiaglobe.com/2026/10/21/defence-minister-bulgarian-aviation-activity-along-black-sea-coast-being-stepped-up/, (Date of Access: 22.10.2026).
[vi] Glenn H. Snyder, “Deterrence and Defense: Toward a Theory of National Security”, Princeton University Press, 1961, ss. 14-16.
[vii] Glenn H. Snyder, “The Security Dilemma in Alliance Politics”, World Politics, 36(4), 1984, ss. 461–495 (Abstract), https://doi.org/10.2307/2010183.
[viii] “Bulgaria Seeks NATO Support to Strengthen Air Defence, Prioritizes Diplomacy over Black Sea Tensions – Defence Minister”, BTA, https://www.bta.bg/en/news/bulgaria/1227281-bulgaria-seeks-nato-support-to-strengthen-air-defence-prioritizes-diplomacy-ove, (Date of Access: 22.10.2026).
