Russian MiG-31 fighter jets were intercepted over Estonia yesterday by NATO aircraft.

09:13, Sat, Sep 20, 2025 Updated: 09:18, Sat, Sep 20, 2025

Putin shakes hands with military official

Putin is believed to be testing NATO's responses with incursions. (Image: Getty)

Experts have said that Vladimir Putin is deliberately provoking NATO in order to learn lessons for potential future conflicts against the alliance. The latest incursion came yesterday when three Russian MiG-31 fighter jetsentered Estonia's air space without permission.

NATO spokesperson Allison Hart called it yet another example of "reckless Russian behavior". The alliance's Secretary General, Mark Rutte, said NATO responded quickly and decisively under Operation Eastern Sentry - the reinforcement of the treaty organisation's eastern flank, including Estonia, after Russian drones flew into Polish airspace overnight on September 9 to 10.

The violation also came six days after a Russian drone was intercepted flying over Romania. The Institute for the Study of War (ISW) wrote in its daily report on Russia's full-scale invasion of Ukraine: "ISW continues to assess that Russia is deliberately attempting to gauge NATO’s capabilities and reactions to various air incursions in hopes of applying lessons learned to possible future conflicts against the NATO alliance."

Russian MiG-31 fighter jets in the air

Russian jets violated Estonian airspace on Friday. (Image: Getty)

UK Foreign Secretary Yvette Cooper said: "The UK stands with our Estonian allies, following yet another reckless incursion into NATO airspace by Russia.

"We must continue to increase pressure on Putin, including driving forward the important new economic sanctions announced by the UK and EU in recent days."

Estonia is one of three Baltic states under constant pressure from the Kremlin.

Researchers say Putin considers their independence and active role in NATO and the EU as threats to Russia’s security, sovereignty, and autonomy.

Estonia’s Foreign Minister Margus Tsahkna said: "Russia has already violated Estonia’s airspace four times this year, which in itself is unacceptable.

"But today’s incursion … is unprecedentedly brazen."

He added: "Russia’s increasingly extensive testing of boundaries and growing aggressiveness must be met with a swift increase in political and economic pressure."

Putin pictured in jacket and tie

The Kremlin sees the Baltic states as imposing on Russian sovereignty. (Image: Getty)

It comes as MPs and peers warned they are "not confident" the UK could protect its undersea cables from attacks that could cause "catastrophic disruption" to the financial and communications systems Britons rely on.

UK offshore cables are "sufficiently vulnerable to make them a target" for Vladimir Putin if he ramps up his tests of NATO's resilience, the National Security Strategy Committee said.

Concerns have been growing about the threat from foreign adversaries to subsea infrastructure critical to internet connectivity.

There is evidence Moscow is preparing for sabotage, with the Russian spy vessel Yantar caught loitering over UK offshore cables in January, the PA news agency reports.