Supreme Allied Commander Europe Alexus G. Grynkewich speaks during a joint press conference with NATO Secretary General Mark Rutte (not pictured), at the Alliance headquarters in Brussels, Belgium September 12, 2025. REUTERS/Omar Havana

By Anthony Deutsch

THE HAGUE, (Reuters) -Russia appears to have been deterred by NATO's firm response last month to incursions into Polish and Estonian airspace, but Moscow is expected to continue testing boundaries, the U.S. general serving as NATO's top commander said on Tuesday.

Three Russian military jets violated Estonia's airspace for 12 minutes on September 19. NATO scrambled fighters and escorted them out, and Washington vowed to "defend every inch of NATO territory."

Nine days earlier, more than 20 Russian drones had entered Polish airspace. NATO jets shot some of them down, the first time an alliance member had fired on Russian targets since the start of the war in Ukraine.

Alexus Grynkewich, a U.S. Air Force general serving as NATO's Supreme Allied Commander Europe, told Reuters in an interview on Tuesday that NATO's responses had sent a message to Moscow.

INDICATIONS RUSSIANS ARE 'TRYING TO BE MORE CAREFUL'

"We do see indications that the Russians are trying to be more careful, that they recognise that they came close to or crossed a line in a couple of cases, particularly when you consider the drone event in Poland," he said.

"We'll have a deterrent effect, but they're going to continue to try to move and take hybrid approaches to how they challenge the alliance."

In the Estonian incident, Russia's Defence Ministry denied the jets violated Estonian airspace, saying they flew over neutral waters. In the Polish incident, Moscow said its drones were engaged in strikes in Ukraine and had not targeted Poland.

After the jets left Estonian airspace "they went very wide and around Estonia," Grynkewich said. "So to me, that shows that they understood that we would respond, that we're able to respond, and that they did not want to have the situation repeat itself."

With major Russian drone and missile attacks targeting Ukrainian cities and power infrastructure ahead of winter, Grynkewich said that the U.S. will continue to supply Patriot missile capabilities "at the rate that meets the Ukrainian needs".

NATO WORKING ON COUNTER-DRONE DETERRENCE

European powers believe Russia was likely involved in a wave of drone incursions in recent weeks, including some that led to severe disruptions at airports in Denmark and Norway. Drones were also spotted over Danish North Sea oilfields in September and disrupted Dutch military exercises in Poland.

Since the first incursions of Russian drones into Poland on September 9, northern European NATO member states have registered at least another 38 incidents spanning Scandinavia, Belgium, and the Baltic states, according to the Washington-based Center for European Policy Analysis.

Russia has repeatedly denied links to these incidents.

Dutch Chief of Defence General Onno Eichelsheim said that NATO will respond to Russian incursions into its territory whether intentional or accidental, and that the alliance is working with Ukraine to counter them.

"The good thing is they (Ukrainians) produce a lot of counter-drone capabilities themselves. So what we have to do is give them the money to produce more," Eichelsheim said after meetings with Grynkewich. "That's one thing we should do in the coming period to provide them with more counter-drone capabilities."

The comments followed a European Commission proposal last week for four flagship European defence projects, including a counter-drone system and a plan to fortify the eastern border, as part of a drive to get the continent ready to defend itself by 2030.

The defence policy "roadmap" reflects fears fuelled by the war in Ukraine, now in its fourth year, that Russia may attack an EU member in the coming years, and calls by U.S. President Donald Trump for Europe to do more for its own security.

(Reporting by Anthony Deutsch and Sabine SieboldEditing by Peter Graff)