Russian Drone Intrusion Sparks NATO Debate Over Deterrence

A Romanian F-16 jet patrol approaches the Ukrainian Border after the Russian drone intrusion (Image Source: The New York Times)

On September 10, 2025, a Russian drone crossed into Romanian airspace, violating the country’s sovereignty and raising concerns about NATO’s ability to take effective measures against external threats. This incursion may seem accidental; however, such violations inadvertently tested NATO’s ability to protect its eastern flank against a hostile anti-NATO power. A state like Romania, which sits directly at the aggressive Russian fault, faces heightened vulnerability to Moscow’s aggression, requiring the implementation of Article 4. This article permits consultations with NATO Member States whenever the security of any of its members is threatened or suspected of being threatened. Article 5, on the other hand, provides a commitment by NATO member states to collective defense only in the case of armed attack. The incident did not meet that threshold, but still tested NATO’s credibility in deterring and responding to hybrid threats. It exposed how even limited violations, such as a drone intrusion, can challenge the alliance’s readiness and unity in protecting its members.

Romania has been a NATO member since 2004 and occupies a hazardous geopolitical location in NATO’s southern part. The 650-kilometer borderline with Ukraine makes the country an indispensable fortress against unforeseeable threats. Romania’s layout facilitates this further, with the Black Sea coastline of the country providing a route for Western military assistance to Kyiv and the air bases utilizing U.S. and French troops from 2022. In February 2025, Romanian lawmakers passed legislation allowing their military to shoot down foreign drones that entered their airspace, illustrating how substantial the threat had become.

The incident on September 13, 2025, was more than a technical failure. Romanian authorities confirmed that the drone was specifically targeting Ukrainian Danube ports when it entered their airspace. The Romanian Ministry of Foreign Affairs described the incursion as "irresponsible" and "unacceptable", indicating a serious level of concern, especially because similar incursions happened just days earlier, with a drone violating Polish airspace too. Immediately after, France was quick to express solidarity with Romania by announcing the deployment of Rafale fighter jets to Romania as part of the recently announced Operation Eastern Sentry.

These provocations underscore the relevance of NATO's founding treaty framework, especially Article 4, in crises. NATO is not always positioned to respond to new threats with force. Due to the consultation principle against new developments, each response frequently begins with re-engaging member states in coordination to prepare for potential military action. 

Article 4 of NATO makes a straightforward statement with substantial implications: “The Parties will consult together whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened.” In effect, Article 4 does not create a legal obligation to take military action. Article 5 commits Alliance members to treat an armed attack on one as an armed attack on all, whereas Article 4 serves as a pathway for political discussion. It requires allies to come together, collect intelligence, assess the threat environment presented by the situation, and decide on courses of action that can range from a diplomatic démarche to a change in military posture.

Article 4 has always carried significant weight within NATO, which is part of the reason it has only been invoked a handful of times in its 75-year history. It is not something to be taken lightly. When it is invoked by a member, that member is signaling to allies and foes alike that the situation has become serious. 

A decade later, Eastern Europe was sounding the alarm. In February 2022, as Russian tanks poured into Ukraine, Poland and the Baltic states invoked Article 4. Their geography and history made them particularly sensitive to Moscow's aggression, and they wasted no time in calling for consultations. NATO met in an emergency session. Troops were deployed in Slovakia, Hungary, Bulgaria, and Romania, while air-policing missions were increased. Practically, this move reassured frontline allies that if challenged, they would not be alone. However, this crisis prompted NATO to warn that the Kremlin could attack the Western world unprecedentedly if they loosen the measures.

Romania’s drone incident was not an independent event but rather the ultimate link in the chain of events that unsettled the eastern flank of NATO. Just a day before the Romanian intrusion, on September 9, Polish authorities claimed that as many as 23 Russian drones came into Poland during overnight strikes against Ukraine. Warsaw swiftly triggered Article 4, demanding consultations with its allies and suggesting that the violation was more than a mistake.

The situation escalated further when Estonia disclosed that three Russian MiG-31 jets had entered its airspace and stayed for around 12 minutes before returning. Tallinn quickly followed Poland's lead and convened Article 4 consultations, claiming these incidents could not be misunderstood as “air operations.”

On the domestic front, the drone incident has internal political ramifications. Since joining NATO, successive governments have continually characterized NATO membership as the clearest guarantee of sovereignty, particularly in consideration of Romania's history involving Soviet influence. Public sentiment remains overwhelmingly positive toward NATO and leaders face pressure to demonstrate that the country is not alone. Romania has made massive investments to modernize its armed forces by purchasing F-16 fighter jets and Patriot air defense systems, as well as hosting multinational battlegroups.

The wider strategic implications extend beyond Romania. Hybrid tactics such as incursions by drones, cyber operations, and disinformation blur the lines between war and peace, challenging the relevance of Article 5 as the only measure for collective action. NATO must respond by clarifying credible responses to existential threats coming from the eastern axis powers. With every attack the Moscow administration actualizes, NATO allies interrogate the credibility of the security pledged in the union

The Romanian drone intrusion once again reminds NATO to be more precarious of ambiguous provocations. From the NATO side, this event underscores the political limitations of responding to the arbitrary actions of enemies who remain at the threshold of war. This circumstance reaffirmed that Article 4 consultations should not simply be gestures of unity but also create tangible reassurance for frontline states. Without decisive action, NATO risks permitting repeated gray-zone incursions and eroding alliance cohesion and deteriorating its deterrent stance.