By Olha Chepil | 2025-10-29

NATO is backing its pledge to defend Europe with action, launching Operation Eastern Sentry, a joint mission to strengthen the alliance's eastern borders after Russian drone incursions into Poland's airspace.

The operation will unite forces from Denmark, France, Germany, the United Kingdom and other allies. It spans NATO's eastern flank from the Baltic to the Black Sea, enabling rapid troop movements, air patrols, naval escorts and ground-based air defenses.

"Eastern Sentry is not just a strategic decision. It is an expression of responsibility for the security of the entire eastern flank of the alliance," Polish Defense Minister Wladyslaw Kosiniak-Kamysz said in September, calling it "active deterrence and readiness to defend wherever needed."

Oleksandr Kraiev, an analyst with the Foreign Policy Council Ukrainian Prism, told Kontur that NATO will redeploy fighter jets from Denmark, France and Germany to Poland for patrols, reconnaissance and target identification.

Shielding Europe's skies

Polish President Karol Nawrocki has approved a decree allowing NATO forces to deploy in Poland under Operation Eastern Sentry, which includes Rafale, F-16, and Eurofighter jets, frigates and new air defense systems.

Kraiev said the operation stands out for its size and mission. It was launched after 19 Russian Shahed drones violated Polish airspace on September 10, prompting Warsaw to invoke Article 4 of the North Atlantic Treaty.

Kraiev noted that the mission aims to counter immediate drone threats. He said "flying expensive F-16s to intercept cheap drones is ineffective" and that NATO seeks more efficient solutions.

Eastern Sentry will integrate air and ground defenses to combat unmanned threats, according to NATO headquarters.

"A number of States are making investments in technologies, learning lessons from Ukraine about what kind of sensors and what kind of weapons, kinetic and non-kinetic, might be effective. And so, integrating those sorts of defenses into our daily deterrence activities and into our regional plans is absolutely going to be something that we want to do moving forward," Alexus Grynkewich, NATO's top commander in Europe, said last month.

Experts believe that Ukrainian experience will become an integral part of the new defense strategy.

"The Ukrainians have unique experience in combating Russian air threats. They will also likely advise the Poles and other NATO countries on countering drones and reconnaissance UAVs," added Kraiev.

On to defense

Russia is no longer waging war solely against Ukraine but is testing NATO's eastern flank from the Baltic to the Black Sea, political scientist Stanislav Zhelikhovsky told Kontur.

He cited repeated airspace violations, drone incursions over Poland and cyberattacks on allied infrastructure as part of Moscow’s pressure campaign.

Zhelikhovsky said the Kremlin is "testing the strength of NATO's entire eastern flank and the European Union as a whole," with incidents occurring more often and penetrating deeper into allied territory.

Analysts view Operation Eastern Sentry as a warning to Moscow that NATO's borders are off-limits.

Zhelikhovsky said the mission marks NATO's shift "from a situational response to a permanent defense presence," signaling that any border violation will draw a response.

He stressed that Ukraine's experience countering Russian air threats has been crucial in shaping NATO’s modernization. Kyiv, he added, serves as a frontline buffer deterring attacks that could threaten NATO members and is ready to "share its experience and be part of the emerging European security architecture."

Ukrainian innovations in electronic warfare, drones and mobile air defenses are feeding into NATO's technological partnerships, Zhelikhovsky said. "We need to prepare for any scenario," he added.

From sea to sea

Despite its ambitions, Eastern Sentry operates strictly within the territory of NATO member states and does not extend air protection to Ukraine. This is an important political consideration intended to avoid direct confrontation with Russia, analysts say.

NATO's Baltic Sentry mission, launched in January 2025, focuses on protecting underwater communications and preventing sabotage. The new Eastern Sentry operation expands that effort to include air defense along the entire eastern flank. Together, the two missions now form a unified defense system for NATO's eastern border.

"The Russian Federation is testing Europe's readiness to counter its threats," Alexander Kovalenko, a correspondent with InfoResist, told Kontur.

By linking maritime and aerial defenses, NATO is creating a single security framework to guard against both underwater and airborne incursions. Zhelikhovsky said the approach aligns with Europe's long-discussed idea of a "united eastern front."

"NATO is building a comprehensive defense architecture for the region's eastern flank -- 'between the seas,'" he said.