Source · Select Committees · National Security Strategy (Joint Committee)
1st Report - Subsea telecommunications cables: resilience and crisis preparedness
National Security Strategy (Joint Committee)
HC 723
Published 19 September 2025
Recommendations
2
Accepted
The Government’s resilience assessments must take greater account of the worsening security environment over the...
Recommendation
The Government’s resilience assessments must take greater account of the worsening security environment over the next 5–10 years. The National Security Strategy and Strategic Defence Review set out serious preparations for future crises. However, the Minister for Data Protection and …
Read more
Government Response Summary
The government agrees to strengthen security, with DSIT writing to operators to request emergency 'good enough' repair plans within 12 months and defining standards. They are also reviewing legislation and will explore similar exercises with European counterparts.
Cabinet Office
View Details →
4
Accepted
The Government should update its public and private risk scenarios to cover extensive co-ordinated sabotage...
Recommendation
The Government should update its public and private risk scenarios to cover extensive co-ordinated sabotage to subsea and terrestrial internet infrastructure, including onward connections to Europe. (Recommendation, Paragraph 39) System vulnerabilities
Read more
Government Response Summary
The government agrees to develop more detailed technical plans for managing cable systems, engage with operators, conduct sector-specific technical impact assessments, and use these findings to inform additional contingency plans and the National Emergency Plans framework for Subsea Cables.
Cabinet Office
View Details →
5
Not Addressed
Many cable landing stations are vulnerable to attack.
Recommendation
Many cable landing stations are vulnerable to attack. The Government and operators must take the risk of state-backed sabotage seriously, including against targets in Europe. (Conclusion, Paragraph 47)
Government Response Summary
The government's response discusses the need for a UK-based and UK-flagged repair ship, which does not address the committee's recommendation about the vulnerability of cable landing stations or taking the risk of state-backed sabotage seriously.
Cabinet Office
View Details →
6
Deferred
The National Protective Security Authority (NPSA) and National Cyber Security Centre should require all UK...
Recommendation
The National Protective Security Authority (NPSA) and National Cyber Security Centre should require all UK landing stations to be target-hardened to sufficient levels to deter state-backed sabotage. They should require landing station operators to develop within 12 months an emergency …
Read more
Government Response Summary
The government requires more time to consider the recommendation, stating the MoD will work with other departments and industry to evaluate commercial cable repair capacity and determine if intervention is needed.
Cabinet Office
View Details →
7
Accepted
To help mitigate risks around the clustering of high value targets, the Government should encourage...
Recommendation
To help mitigate risks around the clustering of high value targets, the Government should encourage subsea cable providers to connect to landing stations, terrestrial routes and data centres outside high-concentration points. (Recommendation, Paragraph 49)
Read more
Government Response Summary
The government agrees with the recommendation and will accelerate work with Lead Government Departments on technical impact assessments to help critical sectors prepare for subsea cable disruption, with oversight from the Cabinet Office’s ‘Undersea Infrastructure Security Oversight Board’.
Cabinet Office
View Details →
9
Not Addressed
The Government’s resilience plans should focus in more detail on the level of immediately available...
Recommendation
The Government’s resilience plans should focus in more detail on the level of immediately available capacity in the cable system during a security crisis. The Department for Science, Innovation and Technology should request operators to provide regular updates on the …
Read more
Government Response Summary
The government's response discusses the National Security Act 2023 and reviewing legislation related to subsea cable sabotage, which does not address the recommendation about focusing on cable system capacity, rerouting data, or developing contingency plans for the Channel Tunnel.
Cabinet Office
View Details →
11
Not Addressed
The Government should acquire a genuinely sovereign cable repair ship by 2030.
Recommendation
The Government should acquire a genuinely sovereign cable repair ship by 2030. This could be leased to industry on favourable terms during peacetime and made available for Government use in a crisis. The Government should set out a timetable for …
Read more
Government Response Summary
The government's response discusses existing international cooperation on cable breaks and vessel behaviour but does not address the recommendation to acquire a sovereign cable repair ship by 2030 or set a timetable for it.
Cabinet Office
View Details →
12
Not Addressed
The Royal Navy should establish a cadre of reservists and serving personnel to learn cable...
Recommendation
The Royal Navy should establish a cadre of reservists and serving personnel to learn cable repair skills on commercial repair vessels. These could be called on in periods of heightened tension. (Recommendation, Paragraph 75) Moderate and catastrophic impacts
Read more
Government Response Summary
The government states it agrees with the recommendation, but the subsequent text discusses sensor and monitoring technologies and their integration with the Royal Navy, completely failing to address the call for training personnel in cable repair skills.
Cabinet Office
View Details →
13
Not Addressed
The UK has particular vulnerabilities around outlying islands, the financial sector and military communications cables.
Recommendation
The UK has particular vulnerabilities around outlying islands, the financial sector and military communications cables. These should be a key focus for contingency planning. (Conclusion, Paragraph 81)
Government Response Summary
The government partially agrees but primarily discusses military deterrence, reviewing concepts, and leveraging alliances, without detailing how specific vulnerabilities around outlying islands, the financial sector, and military communications cables will be a key focus for contingency planning.
Cabinet Office
View Details →
15
Accepted in Part
The Department for Science, Innovation and Technology should ensure all lead departments have detailed sector-by-sector...
Recommendation
The Department for Science, Innovation and Technology should ensure all lead departments have detailed sector-by-sector technical impact studies on areas most likely to be affected and response plans—notably finance, maritime and air traffic, communications, defence and supply chains including food …
Read more
Government Response Summary
The government partially agrees on the importance of a centralised coordination function, establishing an Undersea Infrastructure Security Oversight Board chaired by the Cabinet Office for strategic direction, but does not adopt the specific suggestion to expand SIRG or set up a new inter-ministerial group.
Cabinet Office
View Details →
16
Not Addressed
Emergency services should ensure their business continuity plans highlight any areas of critical reliance on...
Recommendation
Emergency services should ensure their business continuity plans highlight any areas of critical reliance on foreign internet servers, and account for temporary internet disruption in the event of a security crisis. (Recommendation, Paragraph 100) Legal Responses
Read more
Government Response Summary
The government's response discusses exploring cable protection zones and engaging with European partners on maritime infrastructure protection, which does not address the recommendation regarding emergency services' business continuity plans for reliance on foreign internet servers or internet disruption.
Cabinet Office
View Details →
17
Accepted
The legal provisions for responding to malicious cable damage are weak.
Recommendation
The legal provisions for responding to malicious cable damage are weak. It is encouraging that the Government has identified the forthcoming Defence Readiness Bill as a potential legislative vehicle to implement changes. We would like to emphasise the urgency of …
Read more
Government Response Summary
The government accepts the recommendation, agreeing that current legislation for non-foreign power sabotage of cables is weak. It is conducting a comprehensive review of legislation related to subsea cable infrastructure to ensure robust routes for prosecuting private actors.
Cabinet Office
View Details →
18
Deferred
The Government’s review of legislation must pay particular attention to strong deterrents, such as major...
Recommendation
The Government’s review of legislation must pay particular attention to strong deterrents, such as major fines and criminal liability, that can be applied to private actors suspected of working for or on behalf of foreign states. (Recommendation, Paragraph 114)
Read more
Government Response Summary
The government agrees with the recommendation and is closely examining the issue of deterrents, such as major fines and criminal liability for private actors, as part of a comprehensive review of legislation relating to subsea cable infrastructure.
Cabinet Office
View Details →
19
Rejected
The Government should explore new options for taking a more robust approach to interdicting suspicious...
Recommendation
The Government should explore new options for taking a more robust approach to interdicting suspicious vessels—for example applying piracy provisions to cables that land in the UK or seeking a limited extension of domestic criminal law jurisdiction. It should commission …
Read more
Government Response Summary
The government partially agrees but explicitly rejects applying piracy provisions to cables or commissioning an external legal opinion on this issue, citing the importance of consistency with UNCLOS, international partner views, and the risk of reciprocal action. It states options to counter suspicious vessels are kept under continuous review.
Cabinet Office
View Details →
20
Accepted in Part
The Foreign, Commonwealth and Development Office and the Department for Business and Trade should apply...
Recommendation
The Foreign, Commonwealth and Development Office and the Department for Business and Trade should apply diplomatic and economic pressure to press for adequate investigations from flag states and states where vessels suspected of cable damage enter port. The Government should …
Read more
Government Response Summary
The government states it frequently uses diplomatic levers to ensure investigations into cable breaks. It notes existing IMO work on data sharing and mechanisms for reporting vessel behaviour, but states there is a limit to the utility of port inspections as suspicious vessels often avoid such ports.
Cabinet Office
View Details →
21
Accepted
The Government should support the subsea cable industry in rolling out more extensive cable monitoring...
Recommendation
The Government should support the subsea cable industry in rolling out more extensive cable monitoring technology and should explore incentives to encourage such investment. This could include Government commitments to make better use of existing measures and data—for example more …
Read more
Government Response Summary
The government agrees to support the subsea cable industry in rolling out monitoring technology and is already engaged in cross-government cooperation, including commercial relationships and partnerships with the Royal Navy. It will explore better use of existing data, including AIS, and is collaborating across departments to ensure monitoring does not compromise defence or safety, while also considering new legislation.
Cabinet Office
View Details →
22
Accepted in Part
The UK’s military deterrence concepts are too timid.
Recommendation
The UK’s military deterrence concepts are too timid. They need to place greater emphasis on prevention and punitive consequences that go beyond private or public attribution. Otherwise, aggressors that are content with ‘implausible deniability’ can cause damage with minimal risk …
Read more
Government Response Summary
The government partially agrees, stating deterrence concepts are under constant review and leveraging NATO. They acknowledge the importance of effective data sharing, which remains a firm requirement in existing programmes, but do not commit to designing new schemes with NATO for speedy data sharing.
Cabinet Office
View Details →
24
Accepted in Part
The Ministry of Defence should work with international partners to ensure there are viable plans...
Recommendation
The Ministry of Defence should work with international partners to ensure there are viable plans to escort cable ships without degrading wider NATO taskings. This plan could usefully include heightened surveillance of suspicious vessel activity, rules of engagement enabling a …
Read more
Government Response Summary
The government partially agrees, stating escorting ships is an important task and rules of engagement are routinely reviewed. They are investing in new capabilities like underwater drones and the ‘Atlantic Bastion’ concept. They also state the Royal Navy already conducts routine live escorting exercises, which are frequently reviewed, but do not explicitly commit to new plans with international partners or a low threshold for physical interdiction.
Cabinet Office
View Details →
26
Accepted in Part
The Government should seek to provide a joined-up subsea cables function providing a centralised point...
Recommendation
The Government should seek to provide a joined-up subsea cables function providing a centralised point of contact for industry and international partners. This body should co-ordinate, not duplicate, cross-government work—bringing together departments and agencies covering subsea infrastructure operations, policy, security, …
Read more
Government Response Summary
The government partially agrees, accepting the importance of a centralised function but rejecting the upgrade of SIRG and a new inter-ministerial group. They state an Undersea Infrastructure Security Oversight Board has been established to provide a joined-up function and ministerial oversight is already provided by the National Security Council.
Cabinet Office
View Details →
27
Deferred
We support the Crown Estate’s ambitions to improve long-term spatial planning via the Marine Delivery...
Recommendation
We support the Crown Estate’s ambitions to improve long-term spatial planning via the Marine Delivery Route Map. We urge those involved to ensure that plans prioritise a diversity of cable routes to avoid creating areas of concentrated targets. (Conclusion, Paragraph …
Read more
Government Response Summary
The government agrees with exploring cable protection zones and is considering existing powers as part of a comprehensive legislative review. They will factor identified areas of cable concentration into their assessment and are engaging with international partners on maritime infrastructure protection.
Cabinet Office
View Details →
28
Deferred
The Government should further explore cable protection zones for critical areas of cable concentration, policed...
Recommendation
The Government should further explore cable protection zones for critical areas of cable concentration, policed by early warning indicators and heightened monitoring and response capabilities. This would require close co-operation with European partners, given the need to manage other maritime …
Read more
Government Response Summary
The government agrees to further explore cable protection zones, noting potential utility but also jurisdiction limitations and challenges in congested marine environments. They are considering existing powers as part of a legislative review and are engaging with international partners while factoring in existing work on cable concentration areas.
Cabinet Office
View Details →
Conclusions (7)
1
Conclusion
Acknowledged
The UK’s strategic reliance on subsea cables will likely continue for the foreseeable future. The cable industry provides a commendable and commercially efficient repair service, which ensures good resilience against moderate damage. We do not believe there is an imminent threat to the UK’s national connectivity. (Conclusion, Paragraph 14) Threat …
Government Response Summary
The government agrees on the importance of updated risk scenarios and commits to considering how to best update reasonable worst-case scenarios within national risk assessments to reflect the possibility of coordinated sabotage on subsea and terrestrial internet infrastructure.
3
Conclusion
Accepted
We also found sceptical views in some parts of the cable industry about the risks of co-ordinated attacks. We agree that resilience across the sector is generally robust, major disruption is unlikely, and hype is unhelpful. But we caution against adopting ‘business as usual’ industry views to determine national security …
Government Response Summary
The government agrees with the underlying sentiment, committing to ensuring subsea cable infrastructure is geographically diverse and working with industry and Crown Estates to secure space for future routes to support long-term resilience.
8
Conclusion
Not Addressed
The Government’s resilience concept focuses too much on ‘having lots of cables’. This pays insufficient attention to the network’s actual capacity to absorb shocks and does not account for onshore vulnerabilities and long-term trends towards a more brittle system. There is also limited understanding of much damage the system can …
Government Response Summary
The government's response addresses emergency services' business continuity plans and their reliance on foreign internet servers, which does not engage with the committee's conclusion about the government's overall resilience concept regarding network capacity, shocks, and onshore vulnerabilities.
10
Conclusion
Not Addressed
The UK needs more confidence in access to cable repair vessels: the current fleet is ageing, and erstwhile UK businesses have been acquired by foreign entities. (Conclusion, Paragraph 71)
Government Response Summary
The government's response discusses UNCLOS and legal aspects of countering suspicious vessels, explicitly stating it does not accept reliance on piracy provisions or publishing a legal opinion, thereby failing to address the concern about access to cable repair vessels.
14
Conclusion
Not Addressed
The impacts of catastrophic disruption from a co-ordinated attack remain speculative, but are almost certainly highly damaging. We estimate they would include payment and supply chain failures, some degraded communications, overstretched emergency responses, and unexpected cascading issues—all at a time of crisis. We are not convinced there are currently adequate …
Government Response Summary
The government's response discusses escorting ships, investing in underwater drones, and the Royal Navy's exercises, which does not address the committee's conclusion regarding the impacts of catastrophic disruption or the adequacy of sector-by-sector assessments of reliance on subsea cables.
23
Conclusion
Accepted in Part
In a heightened threat scenario, we are uncertain about the Royal Navy’s ability to protect vulnerable cable regions and escort repair ships without undermining commitments to other NATO tasks. We admire the Minister for Armed Forces’ optimism that the problem can be solved with Atlantic Bastion’s future set of autonomous …
Government Response Summary
The government partially agreed with the Committee's concerns, stating it is investing in new capabilities such as underwater drones, autonomous sensors, and new ships under the 'Atlantic Bastion' concept to augment the Royal Navy's ability to protect vulnerable cable regions. It also noted existing routine escorting exercises are conducted and reviewed.
25
Conclusion
Accepted in Part
We commend the Government’s efforts to improve co-ordination, particularly the establishment of the Subsea Infrastructure Response Group and Subsea Communications Cables Industry Group. We accept that changing governance structures for the sake of it is not helpful. Equally, however, there is evidence that improvements to oversight and co- ordination would …
Government Response Summary
The government partially agreed, acknowledging the need for improved coordination but declining to expand the SIRG. Instead, it stated that it has established an Undersea Infrastructure Security (UIS) Oversight Board, chaired by the Cabinet Office, to provide a senior-level, cross-government function for strategic direction and coordination.