It has taken two and a half years of bloodshed in Ukraine, a cascade of Russian missile strikes across Eastern Europe’s periphery, and the unnerving intrusion of drones into Polish airspace, but Nato is finally confronting a grim truth: geography is no longer a shield.
London and Madrid — once thought of as comfortably removed from Moscow’s reach — are now being spoken of by Nato chiefs in the same breath as Tallinn and Vilnius.
On Friday evening, the alliance launched its new mission, codenamed Eastern Sentry, aimed at shoring up Europe’s eastern flank. Yet the message from the press conference announcing it was blunt, even bracing. Mark Rutte, Nato’s secretary-general, flanked by senior American officers, warned that the alliance could no longer afford the luxury of thinking in neat concentric circles of threat radiating outward from Russia’s borders. The line of contact has blurred.
US General Alexus Grynkewich, Nato’s top operational commander in Europe, captured the new mood of urgency. Poland, he said, remains the “first line of defence” against Russian missiles and drones. But that is only half the story. “If they get through,” he cautioned, “the entire alliance could be at risk.” His words were less a warning than an acknowledgement of something European leaders have been privately fearing for months: Russia’s arsenal of hypersonic and long-range cruise missiles has compressed the continent. Distances that once bought precious reaction time have evaporated.
The End of the ‘Buffer Zone’ Illusion
For decades, Western European capitals operated on an implicit assumption that geography equated to security. The Baltic States, Poland and Romania would absorb the first shock of any Russian adventurism; Britain, France and Spain would have time to mobilise. The logic of Nato’s forward-deployed battlegroups, stationed in Estonia, Latvia, Lithuania and Poland since 2017, was built on that premise: to deter Moscow by showing a tripwire presence while the real muscle sat safely in the west.
Eastern Sentry represents a sharp break from that complacency. Rutte, with the candour of a man not yet fully encumbered by the job, admitted that Russia’s new missiles could fly at five times the speed of sound. “They will take five or ten minutes longer to reach Madrid or London than it will take to reach Tallinn or Vilnius,” he said. The arithmetic is chilling. In a real crisis, Britain’s vaunted air defences might have barely a quarter of an hour to respond.
The intrusion of up to 24 unidentified drones into Polish airspace on Wednesday crystallised the urgency. Most were not intercepted. That, as Rutte and Grynkewich both implied, was not through negligence but because Nato simply lacked the right assets in the right places to stop them. It was a sobering admission from an alliance that has prided itself on technological superiority.
A Patchwork Response, but a Start
Eastern Sentry will attempt to close that gap. The mission will knit together air and ground bases across the eastern part of the alliance into a more cohesive defensive network. Denmark has pledged two F-16 fighters and an anti-air warfare frigate. France is sending three Rafales, Germany four Eurofighters, and Britain and other allies are expected to commit forces in the coming weeks.
Sceptics will argue, with some justification, that this is a patchwork rather than a fortress. Two Danish jets will not transform Europe’s security environment. Nor will a lone frigate, however capable. But the significance lies not in the numbers but in the precedent: for the first time since the end of the Cold War, Nato is treating its eastern front as the hinge on which the safety of the entire continent rests.
That is an overdue shift. For too long, there has been a tendency in Western capitals to view the defence of Eastern Europe as a form of altruism — solidarity with allies, rather than self-preservation. Rutte’s remark that “we all live on the eastern flank” should be etched above the entrance of Nato headquarters in Brussels. It reframes the task at hand: not a charitable defence of exposed neighbours, but the forward defence of one’s own homeland.
A Russia That Thrives on Risk
What has forced this rethink is not merely hardware, but Russia’s behaviour. Moscow has become adept at probing for gaps and exploiting Nato’s caution. Drone incursions, cyberattacks, and sabotage on European soil are designed to sit just below the threshold of Article 5, Nato’s collective defence clause. They test resolve without provoking full-scale retaliation.
By failing to shoot down many of the drones over Poland this week, Nato inadvertently encouraged that probing behaviour. The Kremlin will have noted that its harassment yielded no military response. That is precisely why Eastern Sentry matters: it is not only about bolstering defences, but about restoring deterrence. An alliance that cannot protect its airspace loses credibility; and credibility, in deterrence theory, is everything.
Russia’s use of long-range precision weapons has already eroded the old calculus of distance. Its Kh-47M2 Kinzhal hypersonic missile, which reportedly travels at Mach 10, has been fired repeatedly into Ukraine. If deployed from Kaliningrad or western Russia, such a weapon could hit Berlin in minutes and London or Madrid in under twenty. That is the reality behind Rutte’s blunt arithmetic.
Britain’s Role Cannot Be Symbolic
For Britain, the implications are stark. Successive governments have talked of “Global Britain”, projecting power east of Suez while trimming conventional forces at home. But if London is now, in effect, on the eastern flank, that luxury of dispersion will evaporate. The Royal Air Force has been hollowed out to just seven frontline fast-jet squadrons; the Army has shrunk to its smallest size since the Napoleonic era. Such figures might have been defensible when war felt distant. They are reckless when the capital itself could be a target.
Britain’s contribution to Eastern Sentry must therefore be more than symbolic. Typhoons and surveillance aircraft will need to rotate through forward bases, yes, but so will ground-based air defence systems and the logistics to sustain them. The integrated air and missile defence network Nato envisages will stand or fall on whether its western members treat it as their first shield, not someone else’s.
The Wider European Awakening
There are signs that this realisation is spreading. Germany, long allergic to hard power, has quietly begun deploying its own Patriots eastward. France, after years of strategic aloofness, is dispatching Rafales. Denmark’s decision to send both jets and a frigate is symbolically potent: a small nation pulling above its weight.
But the effort remains embryonic. Europe’s air defences are a patchwork of incompatible systems, often short of munitions. Nato has a world-class command structure but scant assets to command. Eastern Sentry can only succeed if it becomes a sustained build-up, not a one-off demonstration. That will mean uncomfortable budget choices, particularly for governments already straining under debt and public unrest. Yet the cost of inaction — leaving Europe’s skies porous — would be infinitely greater.
No Rear Areas Any More
What Rutte and Grynkewich have done, perhaps without meaning to, is bury the last vestige of Europe’s post-Cold War complacency. There are no rear areas any more. A Russian missile does not stop to consult a map of Nato’s forward battlegroups. It simply flies until it hits its target.
The alliance’s founding purpose was to ensure that war, if it came, would be fought far from its members’ capitals. That logic died the moment Moscow demonstrated that it could strike anywhere, at any time. Eastern Sentry is Nato’s first halting attempt to adapt to that reality. Whether it succeeds will depend on whether London, Madrid and the rest of Western Europe grasp that their fate is inseparable from that of Warsaw, Tallinn and Vilnius.
For the first time in decades, Nato’s leaders are admitting the obvious. That is a start. But only a start.
