Russian fighter jets in Estonian airspace: a test of NATO’s unity

On 19 September, three Russian MiG-31 fighter jets violated Estonian airspace above its territorial waters in the Gulf of Finland, remaining there for 12 minutes at a depth up to 10 kilometres. The aircraft were detected, intercepted, and escorted by NATO air forces according to standard procedure: initially by Finnish F/A-18s before entering Estonian airspace, then by a pair of Italian F-35s (deployed to Estonia as part of NATO’s Baltic Air Policing mission), and finally by Swedish JAS 39s up to the border of the Kaliningrad region. In response, Tallinn invoked Article 4 of the Washington Treaty, requesting consultations with allies, and called for an emergency session of the UN Security Council.

The 19 September incident marks the fourth violation of Estonian airspace by Russia this year (in addition, Russian coast guards crossed the maritime border on one occasion). Between 2014 and 2022, the Russian Federation violated Estonian airspace 44 times, including a record 10 incidents in 2016. The vast majority of these incidents lasted less than a minute and occurred over the island of Vaindloo in the Gulf of Finland, where the flight information regions (FIR) of both countries overlap. This is due to the absence of a ratified border treaty and the lack of corresponding adjustments to the FIRs. No violations of Estonian airspace were recorded in 2023 or 2024. However, since the summer of this year there has been a resurgence in Russian activity. The incidents on 22 June and 7 September lasted approximately four minutes each.

As in the past, Russia has denied the accusation of violating Estonian airspace. In a statement issued on the evening of 19 September, the Russian Ministry of Defence claimed that the three MiG-31s had conducted a scheduled flight without crossing any state borders.

The incident fits into a broader pattern of recent escalation by Moscow towards NATO, including airspace violations over Poland and Romania. These actions aim to test allied responses, particularly that of the Trump administration. They form part of a calculated effort to drive a wedge between the United States and its European allies, as well as to deter Washington from further support for Ukraine by signalling Russia’s capability to expand the crisis and destabilise NATO’s eastern flank.

Commentary

• The 19 September incident was an intentional violation of Estonian airspace, significantly more serious than previous cases. It stands out not only due to its scale and duration, but also because of the type of aircraft involved. Brief overflights near the islands of Vaindloo and Hiiumaa, as well as the town of Loksa, could in many cases have been interpreted as accidental. The absence of violations in 2023 and 2024 demonstrates that Russian pilots are capable of respecting Estonia’s borders in the Gulf of Finland – although on 10 June 2024, four Russian aircraft entered Finnish airspace near Porvoo for four minutes and penetrated to a depth of 2.5 kilometres. Moreover, earlier violations of Estonian airspace often involved aircraft posing a lower level of threat, such as the Il-76 or Mi-8. The broader international context is also relevant, with a series of similar provocations in recent months, including against Poland – such as the breach of the security zone around Orlen’s offshore platform in the Baltic Sea – and Romania.

• Tallinn will seek to transform NATO’s peacetime air policing into an air defence mission for the Baltic states. This would involve new rules of engagement, additional missiles for aircraft, and the deployment of ground-based air defence systems. Lithuania, Latvia, and Estonia lack combat aircraft and are entirely reliant on other allies to patrol their airspace.
• NATO, which is responsible for monitoring the airspace of the Baltic states, responded to the incident in line with standard procedures. European allies – including France, the United Kingdom, Germany, and Poland – as well as representatives of the EU and NATO condemned the Russian violation and expressed solidarity with Estonia. So far, there has been no response from the United States. President Trump avoided commenting, citing insufficient information. On 21 September, however, he confirmed that he would come to the defence of Poland and the Baltic states in the event of Russian escalation. Remarks by NATO Secretary General Mark Rutte suggest that the Baltic Air Policing (BAP) mission has now become a part of Eastern Sentry, a broader allied Enhanced Vigilance Activity covering NATO’s entire eastern flank, which was launched on 12 September following the incursion of Russian drones into Polish airspace. At present, the BAP mission consists of 16 aircraft deployed across Estonia (four Italian F-35s) and Lithuania (eight Spanish Eurofighters and four Hungarian JAS 39s). As such, the Article 4 consultations are unlikely to result in a reinforcement of BAP, especially as additional sorties can be provided by Quick Reaction Alert aircraft stationed in Finland, Sweden, Denmark, Poland, Germany, and even the United Kingdom, which also participates in Eastern Sentry. However, Estonia could receive medium-range ground-based air defence systems as part of NATO’s short-term Rotational Air Defence Model. Italy already announced in June that it would deploy the SAMP/T air defence system to Estonia this autumn.

• The escalation of military provocations against NATO’s eastern flank stems from Moscow’s belief that such actions can deepen divisions within the Alliance over how to respond, and may also provoke domestic disputes within member states. The Kremlin is closely monitoring the US reaction and appears to believe that the Trump administration is not prepared to respond decisively – whether through security measures or by tightening economic sanctions. Russia believes that this will lead to rising transatlantic tensions, suggesting further escalation on its part are likely. Moscow’s conduct also has a specific Baltic dimension: it aims to deter coastal states from increasing oversight of so-called shadow fleet tankers, using tactics such as aggressive overflights near vessels or escorting tankers with Russian Navy warships.

Map. Estonian airspace violation (19 September 2025)

Source: Estonian Ministry of Defence.