Russia appears to have been deterred by NATO’s strong response last month to airspace incursions over Poland and Estonia, but Moscow is still expected to test boundaries, General Alexus Grinkevich told Reuters.

On September 19, three Russian military aircraft violated Estonian airspace for 12 minutes. NATO scrambled fighter jets, and Washington vowed to “defend every inch of NATO territory.” Nine days earlier, more than 20 drones entered Polish airspace.

NATO jets shot down several drones, marking the first time an alliance member fired on Russian assets since the war in Ukraine began.

General Grinkevich said NATO’s responses sent a signal to Moscow.

“We are indeed seeing signs that the Russians are trying to be more cautious, acknowledging that in several cases they were close to crossing—or did cross—the line, especially considering the drone incident in Poland,” he said. “We will have a deterrent effect, but they will continue to test and employ hybrid approaches in challenging the North Atlantic Alliance.”