Dr Konstantinos P. Balomenos*

The recent violation of the Polish border by Russian drones on 9–10 September 2025 highlights the intensifying use of hybrid tactics by Russia against its adversaries.

This incident marks a turning point for European security, as it signals that traditional deterrence methods are no longer sufficient. The new reality calls for an urgent reassessment of political, technological and institutional measures. It also underscores the rapid changes in today’s operational environment, where technology and hybrid tactics are shaping new challenges for national defence and security, while defining both deterrence and response capabilities.

In particular, Russian “probing” operations — test actions aimed at gauging an adversary’s thresholds, reactions and resolve without direct escalation into conflict — threaten Europe’s collective security framework and underscore the need to review deterrence mechanisms and cooperation among Alliance member states.

Russia appears to follow a pre-defined modus operandi, exploiting low-cost but high-impact tools to test the limits, resolve and cohesion of NATO and EU member states.

At the same time, third countries such as Belarus — which provide logistical or geographical support — further complicate response planning. Within this context, collective security organisations (NATO, EU, UN) may act swiftly in issuing consultations and condemnations, but moving toward joint operations requires clear political consensus and full legal substantiation.

In other words, Russia seeks to impose political and practical costs on its adversaries without necessarily pursuing outright military victory, forcing Europe to choose between costly deterrence and a new, less secure “normal.”

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Furthermore, Poland’s activation of NATO’s Article 4 consultation mechanism creates new realities for collective security, underlining both the importance of institutional mechanisms to address hybrid threats and the limits of speed and effectiveness in collective response.

The immediate involvement of allied forces — such as Germany and the Netherlands, which worked with Polish forces to shoot down the Russian drones — highlights the practical dimension of collective deterrence and the ability to deliver a coordinated real-time response.

It is noteworthy that this was the first time NATO aircraft confronted a potential threat in Allied airspace, emphasising the need for constant readiness and direct communication between member states.

Specifically, Alliance Patriot air-defence systems detected the drones via radar but did not actively engage them. The night operation included Polish F-16s, Dutch F-35s, Italian AWACS surveillance aircraft, and NATO-managed air-to-air refuelling assets, showcasing the technological and operational coordination required to protect Allied airspace.

For Greece — with its complex geopolitical environment and sensitive borders — Poland’s experience provides important lessons. Despite key differences (Poland facing the Russian threat, Greece dealing with challenges in the Aegean from Turkey), the lessons learned are relevant and can be adapted to each crisis scenario.

The principle that thorough documentation, evidence collection, and timely activation of NATO procedures enable legally grounded and safe action applies regardless of theatre.

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Consequently, the Polish case offers a valuable framework for developing tailored Standard Operating Procedures (SOPs) and Rules of Engagement (ROE), enabling Greece to act lawfully, safely and effectively — while reducing the risk of escalation into a “hot incident.”

The activation of Article 4 and the coordinated allied response confirm the importance of early warning, legal substantiation and the ability for immediate collective action.

For Greece, this underscores the need to strengthen military readiness, expand partnerships and adapt its deterrence mechanisms to hybrid and technologically advanced threats. Such incidents raise complex questions about legality, readiness and strategic decision-making across the Alliance.

Key issues include determining who attributes responsibility for an aggressor’s actions, through which processes, and how robust legal and technical documentation becomes both an operational necessity and a prerequisite for political action and international legitimacy.

These episodes also drive higher defence spending and push European partners toward common air-defence and counter-drone systems — with economic, technological and operational implications for each member state.

In this regard, the May 2024 proposal by Greek Prime Minister Kyriakos Mitsotakis and Polish Prime Minister Donald Tusk to President von der Leyen — for the creation of a jointly funded European “SHIELD” air-defence architecture — remains as timely as ever and vindicates its proponents.

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Moreover, the risk of miscalculation rises, with actions that could quickly escalate a diplomatic crisis into a military confrontation.

For Greece, the Polish experience and the activation of Article 4 offer valuable lessons in practical terms. Greece should follow two parallel lines of action:

• Active participation in EU and NATO diplomatic initiatives, supporting institutional mechanisms, technical attribution processes and evidence-based sanctions.
• Strengthening domestic resilience: upgrading counter-drone capabilities, radar networks and early warning links, enhancing cyber-defence, protecting critical infrastructure, and forming a cross-ministerial crisis group (with MFA, MoD, Public Order, Climate Crisis & Civil Protection, National Intelligence Service, etc.) to ensure coordination and rapid decision-making.

This model should adopt a Whole-of-Government Approach, combining effective diplomacy, military readiness and national resilience — allowing Greece to remain agile, adaptive, decisive and capable of defending its interests while contributing to collective security.

In conclusion, Poland’s response to the Russian drone border violation — and NATO’s subsequent procedures — constitute a significant legal and operational precedent. Greece can use this precedent as a reference point to strengthen the legitimacy and evidentiary basis of its actions in the event of a serious violation of its national airspace.

In a similar case — e.g. the violation of Greek airspace by third-country aircraft or drones — Greece would have the necessary institutional and legal tools to protect its sovereignty, while coordinating with its NATO allies for a collective and legally supported response.

This framework provides security and legitimacy for decision-making without pre-committing the country to specific military actions.

The precedent of the Turkish Air Force’s shootdown of a Russian Su-24M bomber on 24 November 2015 over northern Syria — citing temporary airspace violation — offers a useful historical reference for assessing comparable scenarios.

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Under this logic, Greece approaches the right of self-defence through approval and coordination with relevant institutions, ensuring its actions remain legally justified and consistent with international standards.

This right is exercised within an institutional and collective framework and does not imply automatic escalation in any case.

From this perspective, the legitimacy of any Greek action rests on three key pillars:

• Valid Documentation: radar track recording, ISR/AWACS data, satellite imagery, properly documented evidence and — where allowed — communications intercepts.
• Coordinated Notification: sharing evidence with allies to ensure international support for reaction measures and strengthening collective security.
• Clear Rules of Engagement (ROE): defining gradual escalation from warning to proportional use of force, always within international procedures.

Adopting these processes gives Greece a legally and institutionally solid framework for assessing and handling airspace violations. It reduces political, diplomatic and legal risk, and enhances deterrence — without binding Greece to pre-determined actions.

In short, Greece now possesses a clear and well-documented framework for handling violations of its airspace.

Proactive preparation, internationally recognized documentation, and allied coordination remain the most effective tools to avoid unilateral escalations while strengthening deterrence, legality and regional stability in the Aegean and Eastern Mediterranean.

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*Political Scientist – International Affairs Specialist, Former General Director – General Directorate of National Defence Policy and International Relations (GDPEADS) of the Hellenic Ministry of National Defence (HMoND) 

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*** Original text in Greek. Translated in English for DEFENCE ReDEFiNED