It wasn't the first, second or even third time this year that Estonia has seen its airspace violated by Russian fighter jets. But what happened on September 19 was different, and Estonian lawmaker Marko Mihkelson said this incursion crossed a line. 

"Next time, we're doing that — if you know what I mean," Mihkelson, head of the Estonian parliament's foreign affairs committee, posted on X, referring to 2015, when Turkey shot down a Russian bomber that had briefly strayed into its airspace. 

In 2015, the plane flew above Turkey for just 17 seconds. But, on September 19, Mihkelson described "deliberate flying for 12 minutes" above Estonia before Finnish, Italian and Swedish jets, operating under NATO's new Eastern Sentry mission, escorted three Russian MiG-31s back to their own side.

Mihkelson said it was the most serious Russian violation of Estonia's airspace since 2003, half a year before the Baltic nation joined NATO, which was then interpreted as a clear attempt to try to intimidate Tallinn into changing course.

Defense Minister Hanno Pevkur assured Estonians that NATO pilots had all the necessary authority to down intruders from Russia if there had been any danger to the population. However, that doesn't mean NATO would decide to adopt such a strategy.

More force needed?

On Monday, Poland also positioned itself on the side of firm action in the future. "I want to be very clear," Prime Minister Donald Tusk said. "We will make a decision to shoot down flying objects without discussion when they violate our territory and fly over Poland. There is no room for debate here."

Estonia has invoked Article 4 — for only the ninth time in NATO's history — which can be done when a nation feels its political independence or territorial sovereignty is under threat.

Eyes will be on Tuesday's NATO meeting to see whether it will deliver a clear message. A bigger question looms: what would it take for a situation to escalate to an Article 5-level threat?

Some political analysts echoed Mihkelson, saying a more forceful response is needed. "What does it take? Does it take NATO citizens getting killed?" Kristi Raik, director of Tallinn's International Centre for Defense and Security, told DW on the margins of the Helsinki Security Conference, where NATO's potential response was a recurrent topic.

Raik said Russia had long been trying to find new ways of challenging NATO without crossing the threshold to trigger Article 5 — under which, if a member is attacked, the alliance is obligated to respond.

Russia's Foreign Ministry has acknowledged that MiG planes were in the area, but described their presence as "scheduled flights from Karelia to an airfield in the Kaliningrad region." On social media, the ministry claimed that "the aircraft did not deviate from the agreed route and did not violate Estonian airspace."

Raik said NATO must be ready to act. "We need to give the message that we are serious," she insisted, adding "we have the capability, we have the political will, we have our plans so that if the Russians make more violations that actually threaten the security of any NATO country then they will be shot down."

Pattern of provocation

The Estonia incident is the latest in a series of airspace violations. Those include the unprecedented entrance of 19 Russian drones into Polish airspace on September 10, then one hanging over Romania for an hour a couple days later and other occasions where NATO jets were called into service along the Polish border to ensure no spillover from Ukraine.

Hanna Smith, a hybrid-threat expert currently teaching at the University of Vaasa in Finland, called for a more cautious response, saying it "doesn't need to be as radical as shooting down the plane."

She said calling for more frequent Article 4 consultations had its own value for the alliance as it means that "each and every NATO member can think about: ‘OK, what is our response to that?'"

Advocates of NATO following in the footsteps of Turkey in its forceful 2015 response point out that Russia didn't declare war against Ankara after that shootdown. But Minna Alander, of the Center for European Policy Analysis, also favors holding fire.

"There's also virtue in not overreacting," she told DW at the Helsinki conference. "Russia is so hell-bent on being at war with us, and we just refuse to be at war with them."

Edited by: Jess Smee