European capitals are debating new collective ways to respond to Russian acts of aggression below the level of an armed attack, as some fear existing mechanisms are failing to deter Moscow’s so-called hybrid war.
Countries are split over how to confront the Kremlin’s sustained acts of sabotage, arson and destabilisation, but a growing number are seeking collective processes for punishing Russia over attacks that do not meet Nato’s benchmark to trigger its “article five” mutual defence clause.
“If we are facing hybrid warfare, we need to have hybrid defence,” said Andrius Kubilius, the EU’s defence commissioner. “That’s very clear … We shall look at how to define what means we need to be ready to use.”
EU defence ministers will gather in Brussels on Monday to discuss a proposal from the European Commission to create a new Emergency Security Protocol that could be triggered when countries are hit by such attacks, to co-ordinate effective responses.
This would resemble discussions triggered by Nato’s Article 4 if an ally feels their “security is threatened”. Article 4 has been invoked nine times in Nato’s history, including twice last year.
Multiple European diplomats said that there was widespread confusion over what the new protocol would do, and wariness over any mechanism that could compete with Nato’s processes and potentially make it harder to respond by creating overlapping decision-making pathways.
“I’m not sure that anyone thinks the way to fight back against the Russians is to hold more meetings,” said one diplomat.
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But a majority of countries support rethinking the existing approach to co-ordinating a collective response to Russia’s persistent campaign of destabilising activities this year.
Countries have blamed Moscow for assaults including cyber attacks, the attempted armed drone attack on Leipzig/Halle airport, the blowing up of a rail track in Poland and arson assaults on warehouses and factories. Such incidents have sparked outrage but no clear collective response.
“Very simply, if we are facing painful hybrid threats or actions, our answer should be painful in a similar way,” Kubilius said. “Not similar means [necessarily], but pain should be at the same level.”
“Russia needs to know that there will be answers, and they can be painful,” he added.
In response to sabotage and other attacks broadly classified as “hybrid”, Nato has launched military patrol missions such as Baltic Sentry — which followed the cutting of undersea cables in 2023 and 2024 — and Eastern Sentry, launched after a drone incursion into Poland last year. European countries have also pursued suspects in sabotage cases via joint law enforcement and intelligence missions.
Moscow’s escalating campaign against Nato members, and its use of bombs, fire and other potentially fatal methods of attack, has prompted some officials to propose that European governments stop referring to such assaults as “hybrid”.
Denmark’s intelligence service this week warned that Russia could launch a limited military attack against a Nato country in the coming months.
In her pitch for the new “protocol” earlier this month, Commission president Ursula von der Leyen warned that Russia’s campaign of “cyber attacks and sabotage, arson and drone incursions [is] ramping up every day. So, as the threat level climbs, so must Europe’s preparedness”.
Von der Leyen said Europe’s “doctrine, our institutions and our decision-making have not kept pace with the new reality … we need to consider whether they are still fit for purpose”.
She proposed a new European “counter-hybrid playbook” for the continent to collectively respond to incidents “which fall below armed aggression but clearly threaten our national security. In other words, a mechanism to flank Nato’s ”article four’”.
Defence ministers have been invited to discuss the proposals on Monday, said two people briefed on the preparations.
A Nato official said: “The EU is best placed to comment on EU discussions. The Nato secretary-general has been clear that the strong partnership between Nato and the European Union is more important than ever, and has welcomed European allies stepping up for our shared security.”
“Nato is ready for this. We plan to prepare for this. We have all the response options,” Nato secretary-general Mark Rutte said this week in reference to Russia’s hybrid war.
“[The] only problem is they are not always public, so we cannot always talk about it. They are not always symmetrical. It’s not always tit-for-tat, but I can assure you the Russians know.” – Copyright The Financial Times Limited 2026