Alert – Russia could cause ‘worldwide internet blackouts’ by sabotaging undersea cables as Nato warned over danger posed to ‘defenceless’ cables used for vital infrastructure

Russia could trigger ‘worldwide internet blackouts’ by sabotaging undersea cables with its ‘shadow fleet’, Nato defence chiefs have been warned. 

Telecoms giants fear the critical network of underwater cables are ‘defenceless’ and at the mercy of tyrant Vladmir Putin. 

Writing to the UK, EU and Nato, firms including Vodaphone, O2 owner Telefonica and Orange, warned action was needed following a string of suspected Russian attacks on the data lines. 

In a chilling open letter to defence chiefs, the companies wrote: ‘The repercussions of damage to subsea cables extend far beyond Europe, potentially affecting global internet and power infrastructure, international communications, financial transactions and critical services worldwide.

‘Subsea cable security must be a cornerstone of broader infrastructure protection efforts. By acting now, we can safeguard the networks that underpin our shared future.’

More than 500 cables are used to carry about 95 per cent of all international data. They crisscross the seabed but their remote location makes them hard to defend. 

Several suspected sabotage attacks have already taken place, with defence sources pointing the finger of blame squarely at the Kremlin, amid claims its shadow fleet of commercial vessels had been used. Russia has denied any involvement.

The vast majority of attacks have taken place in the Baltic Sea, were 11 subsea cables have been damaged since October 2023. Similar outages have occurred in the North Sea. 

Fears have been raised Russian tyrant Vladimir Putin could use his so-called ‘shadow fleet’ to cause a global internet blackout by sabotaging undersea cables

Concerns the Russians are planning a sabotage operation have escalated since one of their spy ships, the Yantar, was detected mapping the UK's critical underwater infrastructure in the North Sea in recent months. 

Fears have also been raised about Chinese sabotage after a number of incident around Taiwan. 

In January, defence secretary John Healey described the outages as 'another example of growing Russian aggression'. 

He said: 'I also want President Putin to hear this message: we see you, we know what you are doing, and we will not shy away from robust action to protect this country.'

Dubbed the 'backbone' of Britain, the UK depends on a vast network of gas pipelines, electrical cables and offshore energy hubs to function. But defence officials have become increasingly concerned they could be targeted. 

An attack on any one of these energy pipelines or communications cables could plunge Britain into chaos, disrupting every service, including the NHS.  

MPs on the joint committee overseeing the national security strategy have now launched an inquiry into the UK's ability to protect its subsea infrastructure from attacks. 

Matt Western, chairman of the committee, said: 'As the geopolitical environment worsens, foreign states are seeking asymmetric ways to hold us at risk. Our internet cable network looks like an increasingly vulnerable soft underbelly.'

Russia's Yantar 'research vessel' is widely thought to be a spy vessel. It is fitted with a range of technologies to conduct covert operations deep underwater, including unmanned underwater vehicles and mini-submarines

The Estlink 2 power cable in the Gulf of Finland was ruptured in suspected Russian interference

Britain's Defence Secretary John Healey (R) talks to Commanding Officer of RFA Proteus, Captain Martin Jones (L) as he sits at the dynamic positioning desk on the bridge during his visit to RFA Proteus on February 20, 2025

In their letter, the telecoms giants said network security was an 'absolute priority'. But they warned the rise of attacks by hostile states meant governments needed to step up their security measures.

The firms called for the entire subsea cable network to be classed as 'critical infrastructure' to ensure they are given the appropriate level of protection. 

They also urged the EU, UK and Nato to build greater ties when it comes to intelligence sharing, as well as shared monitoring and surveillance initiatives.

It comes amid fears superyachts belonging to Russian oligarchs were now being recruited to carry out covert operations around the British Isles. 

Russia, a world leader in submarine and undersea technology, routinely sends what it claims are 'research vessels' into waters around Britain and in the North Atlantic.

By the Russian parliament's own admission, these vessels carry a host of technologies, including equipment 'designed for deep-sea tracking, as well as equipment for connecting to top-secret communication cables'.

Some ships, including the notorious Yantar that was warded off by the Royal Navy after it was discovered loitering in the Irish Sea earlier this year, can also deploy unmanned underwater vehicles (UUVs) and mini-submarines to access internet cables and energy pipelines up to six kilometres deep. 

Military and government sources last week told the Sunday Times they suspected superyachts belonging to Russian oligarchs had also been involved in nefarious undersea operations.

Military and government sources told the Sunday Times they suspected superyachts belonging to Russian oligarchs had been involved in covert maritime operations (Pictured: The yacht Amadea of sanctioned Russian Oligarch Suleiman Kerimov. There is no insinuation this vessel conducted spy operations on behalf of the Kremlin)

Autonomous Underwater Vehicle (AUV) at sea. These unmanned robotic craft have revolutionized deep ocean survey and exploration

A handout picture released by the Britain's Ministry of Defence (MOD) in London on January 22, 2025 shows Royal Navy Royal Navy of RFA Proteus (R) patrolling near the Russian vessel Yantar (L), in November 2024

They claimed some of these ships are fitted with 'moon pools' - protected openings in a vessel's hull that allow crews to deploy and retrieve deep-sea diving equipment. Others are able to deploy mini-submarines and submersible crafts.

This allows the stunning yachts to float innocuously on the surface of the water, all while underwater vessels dive deep to sabotage undersea cables or deploy reconnaissance equipment.

Indeed, sources also revealed that the Ministry of Defence and Royal Navy had found reconnaissance devices and sensors in various locations off Britain's coastline.

These devices, some of which were found as early as 2020, are thought to have been deployed to gather data on the movement of Britain's four Vanguard-class nuclear submarines (SSBNs), which constitute the UK's nuclear deterrent.

Some were discovered when they washed ashore, while others were reportedly found by Royal Navy minesweepers. But defence sources admitted they did not know how many sensors were still operational.

Former defence minister Tobias Ellwood has warned that Britain is 'behind the curve' in tracking Russia' deep sea operations. 

Mr Ellwood this week called for a significant expansion of the UK's maritime surveillance capabilities following the reports of Russian spy equipment being seized in domestic waters.

Pipes at the landfall facilities of the 'Nord Stream 2' gas pipeline are pictured in Lubmin, northern Germany

He insisted officials now 'realise that there is a delta between our resilience and the threat that we face'.

'The scale of damage [they could do] is enormous and it's deniable and it's cheap to do,' he told the Guardian. 'That's the worrying dimension of all of this.'

The suggestion that Britain and the West is already involved in a maritime conflict with Moscow was backed up by one senior serving military chief quoted in The Sunday Times.

'There should be no doubt, there is a war raging in the Atlantic. This is a game of cat and mouse that has continued since the ending of the Cold War, and is now heating up again. We are seeing phenomenal amounts of Russian activity.'

A second military source added: 'It's a bit like the space race. This is a world clouded in secrecy and subterfuge … but there's enough smoke to suggest something is on fire somewhere.'

Among the key undersea pipelines potentially vulnerable to saboteurs includes the 700-mile Langeled pipeline from Norway - responsible for a fifth of Britain's entire gas supply. 

With a capacity of 1.4GW and stretching 475 miles, the Viking Link is the longest subsea and land electricity interconnector in the world - yet this too would be worryingly easy for the Russian military to damage. 

As the UK pursues Net Zero environmental targets – leading to the closure of coal-fired power stations – the country has become increasingly reliant on supplies of gas and electricity from abroad in order to 'keep the lights on'.

The Royal Navy's Type 45 destroyer HMS Diamond is seen shadowing suspected Russian spy ship the Yankar through the English Channel 

Indeed, the country is reported to have come close to blackouts during the past winter – saved only by emergency reserves and electricity imported undersea from Denmark. 

Britain and Nato are aware of the threat posed by Russian spy vessels and oligarch pleasure craft alike.

In January, Nato dispatched a fleet of 10 ships to the Baltic Sea to protect Europe's crucial undersea cables.

The ships, which are set to end their deployment this month, conducted patrols in the vicinity of energy pipelines and undersea data cables in an effort to monitor suspicious activity and deter any attempt to sabotage these vital assets.

The move came off the back of a number of disruptions in the Baltic Sea that are widely believed to have been sabotage operations.

In February, Swedish and Finnish police said they were investigating a suspected case of sabotage of an undersea telecoms cable in the Baltic Sea, while Sweden's coast guard deployed a vessel to the location where the damage occurred.

Finnish operator Cinia said it had 'some time' earlier detected problems on its C-Lion1 link connecting Finland and Germany and that it had eventually received confirmation that the cable was damaged even as data traffic continued to flow.

The incident marked the third time in just a few months that the C-Lion1 cable was damaged after it was completely severed in November and December of 2024.

And on Christmas Day in 2024, the Estlink 2 undersea power cable connecting Finland and Estonia was damaged along with four telecoms lines.

Finland seized the Cook Islands-registered Eagle S tanker on suspicion it caused the damage by dragging its anchor, adding that the ship was part of a 'shadow fleet' circumventing sanctions on Russian oil.

Security experts have now argued that British households should follow the example of the EU, which has advised citizens to pack a three-day survival kit.

This should include water, non-perishable food, medicines, a battery-powered radio, a torch, identity documents and a Swiss Army knife.

The protection of critical undersea infrastructure will form part of the Government's Strategic Defence Review (SDR) by former Nato secretary-general Lord Robertson this year.

A source said: 'We know that the Russians are active in the North Sea and have the power to cripple our energy links.

'We need to become much more self-sufficient, and quickly. And households should be ready for all eventualities.'