The Royal Navy is under pressure after suffering “systematic underinvestment”, analysts have warned, as the Russian threat to the seas around the UK intensifies.
Moscow was accused on Thursday of sending fishing trawlers to spy on Britain’s critical undersea cables, with an investigation finding more than 500 instances of Russian civilian vessels loitering above vital undersea cables in the past four-and-a-half years.
The activity, reported on by The Telegraph, indicates that Russian vessels are mapping the locations of fibre-optic cables to allow them to be attacked, potentially disrupting banks, hospitals, transport and mobile phones.
Kevin Rowlands, former head of the Royal Navy Strategic Studies Centre, said the undersea domain is “incredibly important” and “Russia knows of the vulnerabilities here”.
The news emerged as a report from MPs warned the Royal Navy has lost its ability to fight beneath the ice cap, leaving the seas potentially vulnerable to Russian submarines. Sailors need specialist training and equipment to hack through ice, but the last Navy exercises testing this took place in 2018 and the last submarine capable of doing it retired in 2024.
Tan Dhesi, chair of the Defence Select Committee, said Russia was seeking to dominate the Arctic for military advantage, and work to address these gaps “cannot start soon enough”.
There are also concerns about a shortage of Navy captains, after fewer than 10 passed obligatory tests last year – and not a single submarine commander made the cut.
Russia knows the vulnerabilities
Undersea cables carry internet and data vital to modern life, with the Atlantic Council finding that they account for the vast majority of internet traffic and more than $10trn (£7.48trn) in daily worldwide financial transactions.
“There is no ‘cloud’ in the sky,” said Rowlands, an expert at defence think tank Rusi. “Subsea cables carry 97 per cent of our data flows and they are essential to everyday services from health to financial transactions to internet access and, of course, military and intelligence communications between allies.
“We shouldn’t forget energy cables and pipelines. Oil and gas, of course, but we also have an increasing reliance on renewables, especially offshore wind – the energy flows come across the seabed.
“The cables and pipelines aren’t particularly robust in themselves, as we’ve seen from attacks and breaks elsewhere such as in the Baltic, so we need to build redundancy and put protection measures in place, and that is happening.”
These weaknesses are not lost on Russia, which has ramped up activity around the cables in recent years.
Dmitry Medvedev, the former Russian president and a close ally of Putin, stated in 2023 that there were no longer any constraints left “to prevent us from destroying the ocean floor cable communications of our enemies”.
In April, three Russian submarines conducted a “covert” operation over cables and pipelines in waters north of the UK, the Ministry of Defence (MoD) revealed. A British warship and aircraft were deployed to deter the “malign” activity, but there was “no evidence” of any damage to British infrastructure.
Earlier this year, the MoD said Russian submarine activity in the North Atlantic was now back to the same levels as the Cold War era. The US also reported an increase in activity around undersea cables in 2024.
Navy ‘can’t project power like it used to’
Despite the growing threat, Rowlands said that like the rest of the Armed Forces, the Royal Navy “has been stretched, arguably overstretched, in recent years”.
Although an “impressive” building programme is under way – including newType 26 anti-submarine frigates, Type 31 general purpose frigates, and Dreadnought-class nuclear submarines, the existing fleet was “struggling to meet its many competing commitments”, Rowlands said.
“The problems go beyond the ships themselves, though. There has also been systemic underinvestment in the vital but unglamourous supporting infrastructure, including dockyards, housing and communications networks,” he added.
Katja Bego, a senior research fellow at Chatham House’s Europe Programme, said it was clear that “the Royal Navy no longer has the resources and ability to project power like it used to”.
She added: “This is also a matter of prioritisation. The Royal Navy remains good at what it does, despite the pressure it is under, but has been forced to fill a very large brief. Given the current pressures in Europe, it is vital that the UK focus more on its homeland security – including the protection of critical infrastructure out at sea – and provides the Navy with the resources to effectively do so.”
Bego said the Navy needed to be given greater legal levers to combat Russian malign activity in the seas: “Moscow has become increasingly brazen in its actions, the Navy needs to be able to move with the flexibility and speed required to make a fist against these sorts of efforts – whether that’s escorting away suspicious ships or even apprehending them or providing security.”
A Navy insider said that funding to the Armed Forces had been reduced as peace was ushered in at the end of the Cold War in the 1990s, but the “geopolitical situation has now shifted significantly, and we need to reevaluate”.
Emphasising that the force was focused on the North Atlantic and still confident about taking on the Russian threat, they added: “Do we have good kit, good people, and good capabilities? Yes. But infrastructure can’t just be built overnight. It’s been wound down over 35 years, and it takes time to wind it back up again”.
James Cartlidge, shadow Defence Secretary, said that the “threat from Russia, especially in the North Sea and to undersea cables, is growing.
“The Government must improve ship and submarine availability, should accelerate into service the new Type 26 and Type 31 frigates, and deliver more autonomous vessels as part of the hybrid Navy,” he told The i Paper.
“The former prime minister [Sir Keir Starmer] warned that Nato could be at war with Russia as soon as 2030 – for the Royal Navy, this means time is just as important as money.”
Navy still has cards to play
However, Rowlands said that the Navy still retains capacity to respond to Russian warships, spy ships, and shadow fleet tankers in and around UK waters.
It has done extensive work with cable owners, operators and repair companies and introduced two new multi-role ocean surveillance ships, HMS Stirling Castle and RFA Proteus, which are tasked with monitoring and protecting the cable network.
The UK Government is investing £330m specifically for critical underwater infrastructure protection, including upgrades and enhancements to Proteus, and there are expected to be more undersea cable protection capabilities in the coming years, which are likely include drones.
An MoD spokesperson said that the department was “clear-eyed about the threat Russia poses in and around the UK and are unflinching in defending our people and our allies”.
The Royal Navy, in partnership with the Joint Maritime Security Centre, “constantly monitors Russian activity to ensure the security of the UK’s maritime interests”, working with other agencies and law enforcement partners to “ensure fishing and other vessels operate within the law”, the spokesperson said.