Russia is intensifying preparations that could enable attacks on Britain’s undersea cables and pipelines, sharpening concerns over the security of infrastructure that underpins global communications, financial systems and energy supply.
A specialist Russian submarine unit which targets vital undersea infrastructure may be heading to British waters, the head of the Navy has warned.
The Main Directorate of Deep-Sea Research – known by the Russian acronym GUGI – is one of the most secretive elements of Putin’s military.
GUGI vessels are sent to sweep the seabed undetected, tracking down any possible points of vulnerability for countries like the UK which rely heavily on cables and pipes that connect to the continent.
The warning was voiced on December 22, 2025, when the head of the Royal Navy said Moscow has restored elite deep-sea capabilities that allow it to operate at extreme depths, creating the potential for physical interference with subsea assets critical to the United Kingdom.
Royal Navy chief points to revived Russian deep-sea programme
In an interview with the Financial Times, Admiral Gwyn Jenkins said Russia has renewed investment in its Main Directorate of Deep-Sea Research, known as GUGI, after previous technical and organisational difficulties. He stressed that London could not dismiss the threat posed by Russia’s advanced underwater technology and specialised crews.
Jenkins said British intelligence had observed signs that GUGI’s capabilities had recovered and that previously stalled programmes appeared to be active again. As a result, the UK now expects a resumption of operations linked to deep-sea missions near strategically important infrastructure.
While Jenkins declined to define what form a potential “physical impact” might take, he underlined that Russia possesses the means to act if it chooses. Military analysts have suggested this could involve placing explosives at cable junctions or other sensitive connection points.
GUGI’s role in hybrid pressure on the West
GUGI is widely regarded by Western defence officials as one of the most secretive units within Russia’s Ministry of Defence. It operates intelligence vessels and specialised submersibles capable of working at depths beyond the reach of most conventional submarines.
These assets are believed to support not only potential sabotage missions but also intelligence operations, including the installation of monitoring equipment on undersea cables. Such activity could allow Moscow to access confidential data transmitted through transatlantic networks that carry the bulk of global internet traffic and financial transactions.
Western governments see this focus on undersea infrastructure as a deliberate strategy to exploit a critical vulnerability, enabling Russia to exert pressure while maintaining plausible deniability and avoiding direct military confrontation.
Incidents at sea heighten UK concerns
Fears have been amplified by recent encounters involving Russian vessels. In mid-November 2025, the crew of the intelligence ship Yantar, which is associated with GUGI operations, used lasers against pilots of aircraft monitoring the vessel’s movements near sensitive areas.
Following the incident, UK defence secretary John Healey said Britain had prepared “military options” should Yantar pose a direct threat. The episode reinforced anxieties in London about the proximity of Russian ships to vital undersea routes.
British and US officials have repeatedly warned that sabotage of cables and pipelines would likely form part of a broader hybrid campaign combining military, technological and informational tools to destabilise adversaries.
Strategic implications for NATO and the UK economy
Russia’s renewed emphasis on deep-sea operations comes as it seeks alternative ways to demonstrate power amid prolonged pressure from its war against Ukraine. Analysts argue that undersea capabilities offer a relatively low-cost means to intimidate opponents and force them into costly defensive measures.
NATO allies increasingly view GUGI as one of the most dangerous components of Russia’s hybrid strategy. Even the threat of interference compels Western states to invest heavily in monitoring and protection, stretching resources and increasing strategic uncertainty.
For the UK, the risks extend beyond military security. Damage to undersea cables could disrupt financial markets, digital services and logistics networks, exposing economic vulnerabilities that make the issue a growing priority for London within NATO frameworks.