Some of the attacks so far have appeared confusingly random; it’s hard to see how Russia benefits from arson at an IKEA in Lithuania or a small warehouse in London. That’s led to a supposition that Moscow’s primary objective has simply been to foster a general antipathy among European populations toward their governments’ support for Ukraine by sowing fear, uncertainty, and doubt. But few of the attacks have even registered on the public consciousness of the targeted countries, so it’s difficult to see how this amounts to a serious terror campaign.

It’s only after stripping away the seemingly pointless attacks and focusing on those with an obvious objective that the pattern of Russia’s activities in Europe becomes clearer. And that pattern consists of not only actual sabotage but also reconnaissance, probing, and testing in the physical and digital domains, with a focus on communications, logistics, and emergency preparedness.

In 2020, I participated in a study by the Swedish Defence Research Agency, which listed where and how Russia might carry out covert attacks across Europe ahead of an overt military attack on a NATO member—with the aim of immobilizing the continent and rendering it unable to respond.

We’ve seen the items on that list ticked off one by one over the past year, including cyber intrusions; the activation of human assets; the jamming of GPS and other navigation systems, including for aircraft, attacks on subsea communications, and energy infrastructure; and other physical sabotage.

Everything we have seen in Europe suggests that Russia is testing the accessibility of its targets, the impact of its actions, and the reactions by the authorities in the targeted countries.

Each time Russia carries out an attack of this kind, it learns about the target country’s capacity for detecting it, mitigating the consequences, and prosecuting the offenders. All of this helps the Kremlin’s planners identify the softest targets for when they decide the time is right for a full-on campaign.

As Europe scrambles to ramp up support for Ukraine and to determine whether to send troops to support a cease-fire, Russia’s aim could be to intimidate or deter countries from doing so. And the worst-case scenario—preparation for an overt attack on a NATO member state—is still on the table. U.S. Defense Secretary Pete Hegseth’s confirmation of limited U.S. interest in defending Europe last week lent weight to earlier calls for Washington to withdraw its forces from NATO’s eastern frontier. That’s the surest way to turn the possibility of a challenge from Russia into a probability.

We must hope that Russia’s campaign of sabotage and probing is also a learning experience for the target countries, helping them be better prepared for if and when Russia turns up the heat. So far, the publicly known attacks have been individual and isolated; the impact would obviously be much greater if Russia conducted a coordinated mass campaign across multiple locations and domains. That should focus the minds of the governments and the public in Western Europe that have only now realized that they, too, are a target for Russia. Because if NATO’s defense chiefs are right that Moscow is planning military attacks beyond Ukraine, there is no part of Europe that isn’t at risk from Russian efforts to coerce or immobilize the victim and its allies.