Baltic Sentinel

Estonia, small but strategically vital, is once again testing the West’s resolve against Russian assertiveness.

The violation of Estonian airspace by three Russian MiG-31s has led the Baltic nation to invoke Article 4 of NATO’s founding treaty, calling on its allies to consult on collective security. The incursion, lasting a mere twelve minutes, might have seemed fleeting, yet it carries the weight of history. Estonia, perched on Russia’s northwestern flank, is no stranger to threats from its giant neighbour. During the Cold War, it was a republic of the Soviet Union, its autonomy crushed under Moscow’s boot, its people subjected to Russification and political repression. Today, it stands as a NATO member, small in population but strategic in geography, a sentinel whose sovereignty now commands global attention.

With no end in sight of the Russia-Ukraine conflict, NATO’s response was swift and stern. Ambassadors from the alliance’s thirty-two member states convened to underline that any breach of allied airspace – be it that of Estonia’s or Poland’s or Romania’s – was intolerable. It sent a signal that Russia bore all responsibility for such escalatory behaviour.

It was a posture reminiscent of Cold War deterrence. The broader geopolitical echo is clear. NATO’s warning to Moscow was amplified by the United States, with President Donald Trump publicly endorsing a robust response to any future incursions.

Pentagon chief Pete Hegseth assured Estonia that Washington stood by all its NATO allies. Meanwhile, the Group of Seven nations condemned the incidents, promising economic and security measures against Moscow and its enablers. In short, the West is drawing lines around Estonia much as it once did during the bipolar standoff of the twentieth century, only now with different actors and instruments.

Estonia’s alarm is not merely rhetorical. Its borders are among NATO’s most exposed, with the Russian exclave of Kaliningrad to the south and St. Petersburg to the east. The memory of Soviet occupation lingers vividly. Between 1940 and 1991, Estonia experienced annexation, deportation, and the suppression of national institutions. When the USSR collapsed in 1991, Estonia seized the opportunity to restore independence, swiftly building democratic institutions and integrating with Western security frameworks. The country joined NATO in 2004, turning decades of subjugation into strategic leverage and securing an alliance that its Cold War-era citizens could scarcely have imagined.

Today, its airspace, once traversed freely by Soviet bombers with impunity, now carries symbolic significance as it is violated yet again by Russian fighter craft. The breach is a reminder to Estonia that its sovereignty, however internationally recognized, is perpetually vulnerable. For Tallinn, NATO membership is an existential insurance.

The invocation of Article 4 for only the ninth time in NATO’s seventy-six-year history underscores the seriousness of the situation. Twice this month, allies have invoked it in response to incidents over Poland and Estonia, signaling a renewed West-wide sensitivity to Russian adventurism. This comes as Trump finally seems to be warming to Ukrainian President Volodymyr Zelenskyy.

In Estonia, officials emphasized that even accidental incursions would be treated seriously.

Russia’s response has predictably denied any violation, framing Estonia’s claims as attempts to inflame East-West tensions. Yet the pattern is familiar. Moscow has frequently tested the resolve of neighbours, from airspace overflights to cyber incursions and hybrid warfare. Estonia, however, is prepared. Its air defence is integrated with NATO’s, its pilots regularly train with Italian and other allied forces, and its political leadership has cultivated the trust of the alliance.

In the quiet Baltic forests and along the coastline where Soviet tanks once rolled, Estonia now projects confidence. Its challenge is to remain a small nation that matters in a world where Russian power is resurgent, unpredictable, and willing to flout international norms. NATO’s recent warnings, while measured, carry the weight of credibility built over decades of confrontation with Moscow. For Estonia, this is the reassurance that independence, once wrested from the shadow of empire, is now backed by collective will. For the West, it is a reminder that the lessons of history endure: in the Baltic, as in the Cold War, deterrence and resolve remain indispensable.