If Russia thinks NATO is a paper tiger, Moscow must be forced to reconsider.

T he unprecedented has become routine in the skies over Ukraine. So, from the perspective of NATO-based observers, last night’s massive volley of Russian drones and rockets, the volume of which has increased steadily over the summer, looked a lot like the horrible new normal.

Then, as dawn approached in Eastern Europe, NATO air defense assets suddenly began acting erratically — taking to the skies in unusual numbers and racing toward the Polish frontier. Open-source intelligence analysts saw indications that Russian one-way attack drones were making their way toward Polish airspace, and not one or two errant platforms. Then, the information space went ominously dark. For nearly an hour, an eerie silence fell over military and public officials along the Atlantic Alliance’s border — a calm punctuated only by ominous reports that one Polish airport after another, including Warsaw’s two commercial hubs, were closing their airspace.

In the interim, American politicians of both parties filled the void with disturbing and sweeping conclusions. “Repeated violations of NATO airspace by Russian drones are fair warning that Vladimir Putin is testing our resolve to protect Poland and the Baltic nations,” Illinois Senator Dick Durbin wrote. “This is an act of war,” Republican Representative Joe Wilson insisted. “Putin is no longer content just losing in Ukraine while bombing mothers and babies, he is now directly testing our resolve in NATO territory.”

Finally, Polish officials broke their silence. Yes, Russian drones — likely Iranian Shahed drones — penetrated Polish airspace in numbers that do not suggest some wayward ordnance wandered off course. “An operation is underway aimed at identifying and neutralizing the objects,” a Polish military statement read. Polish Prime Minister Donald Tusk subsequently confirmed that a kinetic military operation aimed at taking down hostile Russian drones over Polish airspace was underway. By morning, Poland assessed that 19 large Russian attack drones entered NATO airspace, and it shot down those that posed a threat.

But why? It has not yet been definitively established that the incursion was deliberate. Despite the number of drones that entered Polish airspace, it is not inconceivable that something went wrong on the Russian side. And, knowing what we know about the Russian military, something going wrong in multiple, independent ways would not be particularly remarkable.

And yet, this is an academic question. Even if the event was accidental, the Russians would behave as if it weren’t, and NATO could not afford to treat it as though it were. The alliance must respond to this event as if it were what Polish and European Union officials insist it was: an “act of aggression” that was “intentional, not accidental.”

Of all the places to test NATO’s resolve, Poland is the least fruitful avenue of exploration for Russia. It’s a hard target that spends vast sums on its own defense, and Poland’s baleful history of being abandoned by its Western allies over the 20th century puts the onus on the West to avoid repeating history’s most regrettable errors. Nevertheless, testing NATO’s behavior in response to a Russian incursion provides Ministry of Defense analysts with a wealth of actionable data. If you want to check how NATO assets react to a provocation, you go where the assets are. We cannot be certain that this was not Russia’s objective — not as a prelude to a massive attack on NATO, but to see if it has the will to uphold its commitments.

Moscow likely received discouraging signals from the rapid mobilization it prompted last night. What matters more is how the Atlantic Alliance responds in the coming hours. The Polish government has stated its intention to invoke NATO’s Article Four, which triggers consultations among NATO members in advance of, but not invariably leading to, the invocation of NATO’s Article Five mutual-defense provisions. While rare, Article Four has been triggered before. Turkey, for example, has invoked it more than a half-dozen times this century. But what took place over Poland is direct action from Russia, not its proxies and allies. A serious challenge like this is what NATO was designed for, and the alliance will have to display commensurate resolve to meet it.

It is unclear what that response would or should look like. Provisioning Ukraine with more ordnance to intercept Russian drones and push its forces back toward its own borders would be low-hanging fruit, but that would be a status quo ante response to a new set of circumstances. The live question before NATO members is one that has long been forecast: the establishment of an air-defense zone that includes Western Ukraine, which would involve the deployment of NATO assets to Ukrainian soil.

You can imagine the debate such a proposal would spark in the West. It’s a debate that Vladimir Putin thinks he can win. Many speculated that the Kremlin would one day force the West to confront a “die for Danzig” moment. Is the West really prepared to go to war with the world’s preeminent nuclear power over this? There will be plenty of voices in NATO capitals who caution restraint in the face of this provocation or even blame the West for it. This logic would encourage bolder, more dangerous tests of NATO’s will. Indeed, many such tests preceded this event. The attacks on American businesses inside Ukraine, the strikes on a European Union diplomatic mission, and a British Council annex — it all looks in retrospect like a prelude. In light of that prelude, the drone incursions into Poland are an ominous portent.

Whether accidental or deliberate, NATO’s goal must be to impose more caution on the Russians, and only the tangible and visible signs that the NATO giant is stirred to life will do that.

In some ways, the alliance is fortunate that this long-anticipated provocation occurred where and how it did. The circumstances are more auspicious than a Russian attempt to create de facto conditions on the ground inside a Baltic country and dare the West to attempt to eject them, for example. This is a containable event so long as the alliance’s response to it is robust. For now, the alliance appears united in its shock and determination. But NATO’s skeptics will have their say. Russia’s goal will be to ensure that theirs is the final word.