In a dramatic escalation of tensions between Russia and NATO, a surge of aerial incursions, drone swarms, and military posturing has swept across Europe’s eastern flank throughout September 2025. From the skies above Poland to the naval bases of Sweden, European officials and military analysts are grappling with what appears to be a coordinated campaign by Moscow to test the alliance’s resolve and probe for weaknesses—while Russia’s leaders issue stern warnings and deny any wrongdoing.
The most striking incident unfolded on September 10, when approximately 20 Russian drones flew deep into Polish territory, forcing NATO jets to scramble and shoot them down or chase them until they crashed. According to Associated Press, this marked the first direct military engagement between NATO and Russia since the full-scale invasion of Ukraine began in 2022. Russia denied targeting Poland, and its ally Belarus suggested that Ukraine’s signal jamming was responsible for the drones’ errant paths.
Yet, European leaders saw these actions as deliberate provocations. The following week, Estonia reported that Russian fighter jets penetrated its airspace for a full 12 minutes—a breach described by Estonia’s foreign minister as “unprecedently brazen.” Russia, as usual, denied the incident. Meanwhile, Romania and Latvia each reported single Russian drone violations of their airspace, further fueling concerns that Moscow was orchestrating a broader campaign.
“Maybe their calculation was that now the European countries have to send something additionally to Estonia regarding the air defense assets, and that means they cannot send it to Ukraine,” Estonian Defense Minister Hanno Pevkur told AP. “Russia is trying to tear us out from Ukraine.”
These incidents are part of a pattern that has become increasingly difficult to ignore. On September 25, NATO Air Command revealed that two Hungarian Gripen fighter jets were scrambled in response to Russian Su-30, Su-35, and MiG-31 jets flying dangerously close to Latvian airspace. German authorities, on the same night, identified several unknown drones flying near the Danish border in Schleswig-Holstein, though the origin of the drones remains unclear. That same day, unidentified drones were reported over the Murmelon-le-Grand military base in Marne, France, and Swedish authorities confirmed multiple drone sightings near the naval base in Karlstrona.
Denmark, too, was not spared. Aalborg Airport, which doubles as a military facility, was briefly closed due to drone activity, and Danish Security Intelligence Service Director General Finn Borch Andersen noted that the incidents resembled a “model of hybrid warfare seen elsewhere in Europe.” He assessed a high risk of Russian sabotage in Denmark, even as officials stopped short of directly accusing Moscow of responsibility.
Despite Russia’s denials, the timing and scale of these incursions have led many European and American experts to conclude that Moscow is testing NATO’s air defenses and political will. Mark Galeotti, head of Mayak Intelligence, called the incursions “coercive signaling” designed to discourage NATO from offering robust security guarantees to Ukraine. “This is Moscow trying to say, ‘Just look how dangerous things already are and how dangerous they could get. Remember we are more daring, willful, reckless, resolute—use whatever adjective you want, but the point is, we are more of it,’” Galeotti said on a podcast cited by AP.
Edward Lucas, a senior fellow at the Center for European Policy Analysis, suggested that Russia’s aim may be to plant doubt among NATO allies: “Are you willing to go to war with Russia on behalf of the Baltic states?” Lucas wrote, warning that Russia could defeat NATO politically if it manages to sow mistrust within the alliance.
Inside NATO, the response has been swift but not without internal debate. After the drone swarm over Poland, Warsaw triggered a NATO mechanism that allows any member to demand a full meeting if its territorial integrity is threatened. The alliance soon launched an operation to bolster air defenses along its eastern flank. Further discussions were held on September 23 and again on September 26 in response to the escalating airspace violations.
Prime Minister Donald Tusk of Poland declared his country would, “without discussion,” shoot down any object that flies into its territory. But cracks in the alliance’s approach soon appeared. NATO Secretary-General Mark Rutte stated that decisions to fire on intruding aircraft would depend on “available intelligence regarding the threat posed by the aircraft.” Meanwhile, U.S. President Donald Trump initially suggested the drone intrusion into Poland “could have been a mistake” but later, under pressure, affirmed that NATO should shoot down intruding Russian aircraft. However, he declined to commit the U.S. to direct military involvement if such a confrontation occurred.
Russia, for its part, has continued its rhetorical offensive. On September 25, Foreign Minister Sergei Lavrov told the G20 Foreign Ministers’ Meeting that “the collective West provoked the war in Ukraine” and accused NATO and the EU of declaring a “real war” on Russia through Ukraine. The next day, Russian Ambassador to France Alexei Meshkov warned that Russia would consider it an act of war if NATO countries shot down Russian aircraft “allegedly” violating airspace, and accused Europe of failing to provide evidence of Russian involvement in drone incursions.
While European defense ministers met on September 26 to discuss a “drone wall” along the EU’s border with Russia and Ukraine, intended to detect, track, and intercept drones, Russian officials continued to frame the West as the aggressor and threatened further escalation if NATO responded militarily. EU Commissioner for Defense and Space Andrius Kubilius insisted that the response must be “firm, united, and immediate,” emphasizing the need to improve drone detection and interception capabilities.
Meanwhile, the conflict in Ukraine grinds on. Ukrainian President Volodymyr Zelensky, during a September 23 meeting with President Trump, requested additional long-range missiles and approval to strike military targets inside Russia. Trump reportedly did not oppose the idea, but stopped short of promising to lift restrictions. On September 26, Ukrainian Commander-in-Chief General Oleksandr Syrskyi announced the creation of a new Unmanned Air Defense Systems service to deploy interceptor drones against Russian Shahed-type drones.
On the battlefield, Ukraine’s military reported striking the Afipsky Oil Refinery in Russia’s Krasnodar Krai between September 25 and 26, damaging a major crude oil processing unit. Ukrainian Special Operations Forces also updated their assessment of an August 9 strike on the Russian 448th Missile Brigade in Kursk Oblast, reporting the destruction of missile launchers, air defense systems, and warehouses.
As September draws to a close, the skies over Europe remain tense, with each new drone sighting or airspace incursion adding to the sense of unease. Whether Russia’s actions are meant as a warning, a test, or a diversion, the message is clear: the boundaries of confrontation are being pushed, and the stakes for both NATO and Russia have never been higher.