The UK Government has been warned it is “too timid” in defending the country’s undersea internet cables, with a new parliamentary report calling for urgent action to strengthen resilience and deterrence against hostile actors.
The cross-party Joint Committee on the National Security Strategy has concluded that subsea cables—responsible for transmitting 95–99% of global internet traffic—remain a critical vulnerability. The UK, almost entirely reliant on these cables for international connectivity and serving as a hub for transatlantic traffic, faces growing risks amid worsening geopolitical tensions.
The Committee stressed that while the industry has built “commendable” resilience against routine damage, government planning has underestimated the scale of the threat. The report states:
We can no longer rule out the possibility of UK infrastructure being targeted in a crisis. We are also not confident that the UK could prevent such attacks or recover within an acceptable time period.
Key Risks
The Committee highlighted the financial sector, military infrastructure, and UK outlying islands as areas of particular risk. Catastrophic disruption from a coordinated attack could include failures in payments systems, degraded emergency services, and cascading failures in authentication systems.
Here are some of the mentioned scenarios in the report:
- Recent Russian naval activity, including the Yantar spy ship loitering over UK subsea assets.
- Non-state actors targeting cables, such as Houthi attacks in the Red Sea in 2024.
- September 2025 disruption of Microsoft Azure cloud services linked to cable damage.
- High-capacity cables concentrated in few landing points and data centers, creating “high-value targets.”
- Vulnerabilities at onshore landing stations, which remain exposed to unsophisticated sabotage.
Eight Core Recommendations
To mitigate these risks, the Committee outlined a detailed set of recommendations:
- Sovereign Repair Ship: Acquire a UK-flagged cable repair vessel by 2030, leased to industry during peacetime but available for government deployment in a crisis. The vessel should be integrated into military exercises to ensure protected repair capacity during conflict.
- Reservist Training Scheme: Establish a cadre of Royal Navy reservists and serving personnel with cable repair skills, including jointing, deployment, and handling operations. This would ensure sovereign expertise in the event commercial operators are unavailable.
- Legal Reform and Sanctions: Update outdated frameworks, introducing tougher penalties for malicious damage, testing anti-piracy provisions, and expanding port-state control to better police suspicious vessels. The aim is to impose “genuine costs” on hostile actors.
- Integrated Monitoring Systems: Deploy new distributed acoustic sensing and other subsea monitoring technologies, combined with early-warning systems and real-time data sharing with law enforcement. Monitoring would also target vessels switching off automatic identification systems (AIS).
- Sector Contingency Planning: Improve impact assessments and resilience planning across key industries, including finance, telecoms, and emergency services. Operators should regularly share traffic data, spare capacity, and rerouting capabilities with government agencies.
- Onshore Infrastructure Security: Designate all landing stations as Critical National Infrastructure, upgrade site security, and develop “good enough” emergency repair plans to rapidly restore minimal connectivity under attack scenarios.
- Cable Route Diversification: Reduce clustering of cables and data flow through a handful of routes and data centers. New subsea and terrestrial pathways should be developed to limit dependence on high-value choke points.
- Cross-Government Coordination Unit: Establish a central body to align national security priorities with commercial realities. This unit would coordinate contingency planning, manage crisis exercises, and address gaps between government expectations and industry capabilities.
Industry-Government Tensions
The Committee expressed concern over “business as usual” attitudes in parts of the industry and government, which it said underestimate the risks of coordinated attacks. It warned that focusing only on fishing accidents or accidental anchor dragging is inadequate:
The Government’s resilience concept focuses too much on having ‘lots of cables’ and pays insufficient attention to the system’s actual ability to absorb unexpected shocks.
Matt Western, Chair of the Committee, underscored the urgency of change:
The scale of the UK’s strategic reliance needs to be taken more seriously. While our national connectivity does not face immediate danger, we must prepare for the possibility that our cables can be threatened in the event of a security crisis.
He added: “The Government must raise its gaze. Focusing on fishing accidents and low-level incidents is no longer good enough. We need stronger physical protections, better options to impose genuine costs for malicious activity, and more comprehensive recovery plans. It is conceivable that the UK’s national resilience will be tested in the coming years. We need to be ready.”
Strategic Outlook
The Committee’s findings mirror a wider recognition across NATO allies that subsea infrastructure is an increasingly contested domain. With Russia considered the most immediate threat, and China, non-state actors, and autonomous systems posing emerging risks, the UK faces a future in which deterrence, sovereign capacity, and rapid repair capabilities will be essential.
For subsea operators, infrastructure providers, and investors, the report signals increased regulatory attention and likely government involvement in resilience planning. It also highlights an opportunity for the industry to collaborate more closely with defense and security bodies, as cable networks shift from being seen as a commercial utility to a matter of national security.
