Last Friday, the quiet skies over Estonia’s Gulf of Finland were shattered when three Russian MiG-31 fighter jets streaked into the country’s airspace, setting off a chain reaction of diplomatic outrage, military mobilization, and urgent international debate. As the world watched, NATO scrambled to respond—both in the air and at the negotiating table—while the incident reignited long-simmering questions about the alliance’s rules of engagement and its willingness to confront Moscow’s provocations head-on.
The facts are stark: on September 19, 2025, according to multiple sources including CNN and Ukrinform, the Russian jets entered Estonian airspace without permission and lingered for a tense 12 minutes before being intercepted and forced to retreat by NATO fighters. Estonian Prime Minister Kristen Michal wasted no time, calling the intrusion “unprecedented and brazen” and invoking NATO’s Article 4, which allows any member state to convene the alliance for urgent consultations when its security is threatened. "Such violation is totally unacceptable. The Government of Estonia has decided to request NATO Article 4 consultations," Michal announced on X.
Defense Secretary Pete Hegseth echoed the alarm, declaring the incursion “unacceptable” and reaffirming U.S. solidarity with Estonia. “The Russian incursion into Nato airspace is unacceptable. The Department of War stands in solidarity with Estonia and commends the rapid, strong allied response,” Hegseth posted on social media. Estonia’s Foreign Minister Margus Tsahkna, speaking to NPR, underscored the seriousness of the event and the need for a robust NATO response.
This was not an isolated episode. In the days leading up to and following the Estonian incident, Russian drones and jets were spotted over Poland, Romania, and even as far west as Denmark and Norway. On September 22, large drones forced the temporary closure of airports in Copenhagen and Oslo—an event Danish Prime Minister Mette Frederiksen called “the most serious attack on Danish critical infrastructure.” While Russian officials denied involvement, European Commission President Ursula von der Leyen called the drone flights part of a “pattern of persistent contestation at our borders.”
At an emergency meeting of the UN Security Council requested by Estonia, European and American officials issued their sternest warnings yet. British Foreign Secretary Yvette Cooper warned Moscow that it was risking “a direct armed confrontation between NATO and Russia,” adding, “Our alliance is defensive, but be under no illusion … if we need to confront planes that are operating in NATO airspace without permission, then we will do so.” U.S. Ambassador to the UN Michael Waltz was equally blunt: “The United States and its allies will defend every inch of NATO territory.”
Polish Deputy Prime Minister Radosław Sikorski was unsparing in his condemnation, telling the Russian delegation, “If another missile or aircraft enters our space without permission - deliberately or ‘by mistake’ - and gets shot down, and the wreckage falls on NATO territory, please don’t come here to whine about it. You have been warned. Thank you.”
For its part, NATO issued a strongly worded statement on September 23, denouncing Russia’s “dangerous violation of Estonian airspace” and describing it as part of a “wider pattern of increasingly irresponsible Russian behavior.” NATO Secretary General Mark Rutte told reporters in Brussels, “Russia should be in no doubt: NATO and Allies will employ, in accordance with international law, all necessary military and non-military tools to defend ourselves and deter all threats from all directions.”
But behind the tough rhetoric, a thorny dilemma loomed: why didn’t NATO jets, specifically the Italian F-35s scrambled as part of Operation Eastern Sentry, shoot down the Russian intruders as Turkey did a decade ago when it downed a Russian Su-24 for a brief airspace violation? The answer, experts say, lies in the alliance’s complex rules of engagement and the realities of military capability. As Ukrainian Air Force officer Anatoliy Khrapchynski explained to Ukrinform, “Could Estonia have shot down a Russian fighter jet... like Turkey did in 2015? No, it couldn't. It's inappropriate to compare the capabilities of these two countries. Estonia actually doesn't have its own fighters, and there are as well big problems with air defense systems. Estonia is forced to rely on NATO. And the decision - to shoot down or not - is made by NATO.”
NATO’s protocols require a graduated response, starting with warnings and interception before resorting to lethal force. The Russian jets, while armed with R-73 air-to-air missiles, did not pose an immediate threat to ground targets, and their incursion—though provocative—did not cross the threshold for direct engagement. “The Russian airplanes were ‘at gun point’. Believe me, the MiG is no competitor to the F-35... In my opinion, NATO acted appropriately. At least in this specific situation,” Khrapchynski added.
Political analysts argue that Moscow’s tactics are designed to probe NATO’s resolve and exploit any perceived hesitation. Ihor Reiterovych, a political scientist, sees a deliberate escalation: “At first the Kremlin launched drones, followed by airplanes.” He advocates for asymmetric responses, such as a no-fly zone over parts of Ukraine or cyberattacks targeting Russian infrastructure. Others, like Oleh Sahakyan, suggest moving from mere deterrence to active prevention of further Russian aggression, including major naval exercises or technological countermeasures.
The incident has also prompted calls within NATO to revisit its rules of engagement. The North Atlantic Council convened on September 23 to discuss whether to update the alliance’s definitions of “hostile intent” and “hostile act,” which determine when military force can be used. The debate is far from academic: as Czech President Petr Pavel warned, “In these times, we must act firmly, and if violations occur, we must respond accordingly, including militarily. Russia will very quickly realize it has made a mistake and overstepped its bounds. Unfortunately, this is balancing on the brink of conflict, but giving in to evil is simply impossible.”
Meanwhile, the Baltic states are taking matters into their own hands. Lithuania’s parliament recently authorized its military to shoot down drones violating its airspace, while Sweden has warned it will do the same with Russian jets. The message from Europe is clear: patience with Moscow’s provocations is running thin.
Yet, as the dust settles over Estonia, the broader challenge remains. The security of NATO’s eastern flank is inseparable from the fate of Ukraine, whose struggle against Russian aggression continues to shape the balance of power in Europe. As President Trump weighed in, expressing confidence that Ukraine could reclaim its lost territory with Western support, the stakes could hardly be higher. The next violation—whether by drone or jet—may force NATO to decide, once and for all, where its red lines truly lie.
The skies above Estonia may have quieted for now, but the alliance’s response—or lack thereof—will echo far beyond the Baltic, testing the credibility and unity of NATO as it faces its most serious challenge in a generation.