Iran’s threat to destroy submarine telecommunications cables beneath the Strait of Hormuz has raised fresh questions about the security of Scotland’s internet connections, following repeated cable failures that have already left communities in the Northern Isles without reliable communications.
Although an attack on the Persian Gulf cables would be unlikely to disconnect Scotland from the internet, the confrontation has exposed a wider concern: Britain’s dependence on vulnerable infrastructure beneath the sea, the limited ability of satellite networks to replace it, and the consequences for communities with few alternative connections.
The warning comes amid renewed military confrontation between Iran and the United States. On 14 November, Iran’s navy reported that three oil tankers had struck mines and caught fire in the Strait of Hormuz. The claims had not been independently verified.
Communications cables are now among the infrastructure Tehran has explicitly threatened to target.
Iran Says It Has Plans to Attack Internet Cables
On 21 October, Iranian Revolutionary Guards official Yadollah Javani warned that important communications cables crossing the Strait of Hormuz could become targets if Iranian infrastructure came under renewed attack.
Two days later, Reuters reported that two senior Iranian security officials had confirmed the existence of plans to damage submarine telecommunications cables in the Gulf.
One official said Iran would also seek to prevent repairs, potentially prolonging the disruption to internet services and other communications.
The threat extends beyond military installations. Submarine cables carry commercial internet traffic, financial transactions, business communications and information exchanged between data centres.
Attacking them could affect countries that are not directly participating in the war.
The warning has also been circulated online in more dramatic terms, including suggestions that an American strike on Tehran would automatically trigger the destruction of cables and cause a worldwide internet blackout.
The available reporting does not establish such an automatic response, and the claim of an impending global internet shutdown is not supported by telecommunications data.
No independently verified Iranian operation severing the threatened telecommunications cables had been established by 15 November.
How Much of the World’s Internet Passes Through Hormuz?
The Persian Gulf’s importance to shipping and its importance to internet traffic is substantial.
The Strait of Hormuz is one of the world’s most important oil and gas shipping passages. It is not, however, the principal corridor carrying international internet communications.
The International Cable Protection Committee, which represents the submarine cable industry, states that less than one per cent of worldwide international telecommunications bandwidth passes through the Strait of Hormuz.
The committee identifies five active submarine cable system segments crossing the strait, alongside other systems under development.
Iranian officials have referred to seven major cables. That figure should not be confused with the committee’s count of currently active crossings; the two descriptions have not been publicly reconciled.
The threatened infrastructure is particularly important to communications serving Bahrain, Qatar, Kuwait and other Gulf countries. These networks also connect regional data centres and businesses to international destinations.
Damage to several cables could create serious disruption in those countries, especially if repairs were prevented by military activity or restrictions on repair vessels.
But the suggestion that their destruction would eliminate most global connectivity confuses two different statistics.
Approximately 99 per cent of Britain’s international data traffic travels through submarine cables. That does not mean 99 per cent of its international traffic passes through the Persian Gulf.
Most of the UK’s international connections use other routes, including cables across the Atlantic and links to continental Europe.
For Scotland, widespread loss of internet service caused solely by damage to cables inside Hormuz is therefore unlikely. Disruption to particular overseas banking, cloud-computing or communications services remains possible.
Scotland’s Vulnerability Is Much Closer to Home
The Iranian threat coincides with growing concern over the resilience of submarine cables serving Scotland’s own communities.
Shetland and Orkney have experienced repeated telecommunications failures, demonstrating that the damage to relatively small numbers of cables can have serious consequences when alternative connections are limited.
On 20 October 2022, Shetland suffered a major interruption to telephone and internet services following damage to submarine telecommunications cables.
Police Scotland warned that some residents might be unable to contact emergency services by conventional means. Officers were deployed to patrol communities, while residents were advised to check on vulnerable neighbours.
The force also warned that assistance alarms might not operate correctly.
The incident illustrated a problem extending well beyond household broadband. Telecommunications outages can affect healthcare appointments, emergency calls, electronic payments, businesses and the public services that depend on them.
Further disruptions occurred in 2025.
During a Scottish Parliament debate on 8 October 2026, MSPs examined the damage caused to the SHEFA-2 telecommunications system, which connects Shetland and Orkney with wider networks.
The debate recorded that a cable damaged by fishing activity off Orkney in July 2025 had left some customers without service for 12 days.
A further rupture in October 2025, associated with severe weather, caused outages lasting as long as 26 days for some users.
Parliament was also told that the SHEFA-2 system had suffered 20 serious breaks over 19 years.
The outages did not affect all customers equally. Some services could be transferred onto alternative routes, while others remained disconnected.
This demonstrates the difference between having several connections and having sufficient working capacity to keep essential services running when one fails.
None of those Scottish incidents has been established as Iranian activity or deliberate foreign sabotage.
Nevertheless, they provide documented evidence of how the loss of physical telecommunications infrastructure can affect everyday life.
The Scottish Government Is Examining Another Cable to Shetland
Scotland’s exposure is recognised in the Scottish Government’s current plans.
Its Programme for Government 2026–2031 commits to initiating a feasibility study of another submarine telecommunications cable between Shetland and mainland Scotland.
The stated objective is to increase resilience and reduce the risk of service disruption.
The commitment is significant because improving the capacity of an existing cable is not necessarily equivalent to providing an independent route.
If several services rely on the same physical cable, landing station or network equipment, damage to that shared infrastructure can interrupt them simultaneously.
An additional connection becomes particularly valuable when it follows a genuinely separate route and has sufficient capacity to take over essential communications.
For island communities, this raises questions about the number of independent routes available, how rapidly traffic can be transferred between them and whether emergency communications can continue during a prolonged failure.
The government’s feasibility study is not itself a completed replacement cable, and its eventual cost, route and delivery timetable remain to be determined.
Britain Has 64 Submarine Cable Systems, but Their Number Is Not a Guarantee
The UK Government published a white paper on critical undersea infrastructure security on 22 October, one day before the Reuters account of Iran’s detailed attack plans.
The government identified 64 active submarine telecommunications cable systems landing on UK shores, comprising 45 international systems and 19 domestic systems connecting the mainland and offshore islands.
These routes give Britain substantial resilience against the failure of individual cables.
However, the Joint Committee on the National Security Strategy warned in its 2025 investigation that the number of cables alone does not demonstrate how well the overall network would survive a coordinated attack.
The committee raised concerns about network capacity, dependence on particular landing stations, the ability to reroute traffic and the absence of a single authority with comprehensive oversight of the entire system.
It also questioned whether the UK’s contingency planning adequately accounted for attacks affecting both transatlantic and European routes.
The new government white paper proposes stronger criminal penalties for harmful interference with undersea infrastructure, additional security obligations for operators and new national-security powers.
These are proposals subject to consultation and subsequent legislation, not protections that can be assumed to be fully operational today.
The distinction matters because most submarine cables are commercially owned or operated. Their security depends on coordination between private operators, telecommunications providers, governments and maritime authorities.
How Dangerous Would a Coordinated Cable Attack Be?
Britain’s National Risk Register 2026 provides a more severe scenario than anything currently threatened in the Strait of Hormuz.
It examines the consequences of most of the direct transatlantic cables connecting Britain to North America becoming inoperable over a short period.
Under that hypothetical scenario, the government anticipates slow or unreliable internet services for up to three days while telecommunications operators reorganise international traffic.
Some specialist connections could remain impaired considerably longer, and physical repairs could take months.
The consequences could extend to financial services, transport, supply chains, government functions and businesses dependent on overseas systems.
Emergency services are expected to continue operating, although supporting communications systems could come under pressure.
This is not a forecast of an Iranian attack on Scotland. It is an illustration of the potential consequences of extensive damage to major routes upon which Britain directly depends.
The International Cable Protection Committee also cautions against assuming that all suspicious cable damage is sabotage.
Its industry data indicate that approximately 150 to 200 submarine telecommunications cable faults occur worldwide annually. Around 70 to 80 per cent are associated with accidental human activity, particularly fishing equipment and ships’ anchors.
Nevertheless, deliberate attacks remain a security concern because simultaneous damage to several routes could overwhelm the redundancy normally used to manage accidental faults.
Can Satellite Internet Replace the Cables?
Satellite communications offer an important alternative, particularly for remote Scottish communities, but they cannot replace the total capacity of submarine fibre-optic networks.
The parliamentary investigation into submarine cable security estimated that satellite systems could typically handle only around five per cent of the data capacity provided by submarine cables.
Modern fibre-optic systems can carry enormous quantities of international traffic simultaneously, making them essential to banking, cloud computing, telecommunications and the operation of large digital platforms.
Satellite systems are better suited to providing alternative access for individual premises, remote facilities and essential communications during local outages.
Low Earth orbit services such as Starlink have already become increasingly important in Scotland.
Ofcom’s Connected Nations 2025 report recorded more than 15,000 Starlink subscriptions in Scotland, compared with approximately 11,000 in 2024.
Around 2,000 of those subscribers were in locations without access to decent broadband through other available technologies.
For an island household or business whose terrestrial connection has failed, satellite broadband could provide a valuable alternative.
However, its effectiveness depends on the availability of the satellite service, functioning equipment, sufficient electricity and the continued operation of the wider networks that carry data onward.
Installing a satellite terminal does not automatically make an organisation’s websites, banking systems or cloud applications independent of terrestrial infrastructure.
A business could retain satellite internet at its premises while still being unable to use an overseas service whose data centre or network had been damaged.
Satellite communications are therefore best understood as a means of improving resilience, rather than a replacement for the international fibre-optic system.
What Would an Iranian Attack Mean for Scottish Households and Businesses?
If Iran damaged several cables in the Strait of Hormuz, the most serious direct consequences would probably be concentrated in the Gulf.
For most Scottish homes, there is no evidence that such an attack would cause a nationwide broadband blackout.
Some Scottish businesses could nevertheless experience indirect disruption if they use financial institutions, communications networks or cloud-computing services dependent on affected infrastructure.
Problems could include interrupted international transactions, temporary loss of access to overseas applications, slower connections to particular destinations or delays affecting commercial services.
The extent of those effects would depend on where a business’s services are hosted and whether its providers have alternative routes.
The risk to Scotland would become substantially more serious if the conflict expanded to other important telecommunications corridors, particularly routes linking Europe with Asia through the Red Sea, or if unrelated attacks damaged infrastructure serving Britain itself.
Those are separate scenarios and should not be treated as inevitable consequences of the Iranian warning.
For Scottish public authorities and businesses, the practical questions concern the physical location of critical systems, the existence of independent communications routes, backup power and the ability to continue essential functions without a permanent internet connection.
A medical practice, ferry operator, care service or retailer may require more than one communications supplier. It must also establish whether those services depend on the same physical infrastructure.
The Shetland outages demonstrated that the presence of alternative connections does not always ensure they can immediately carry the necessary traffic.
A Warning About Scotland’s Digital Dependence
Iran’s threat has brought the security of submarine telecommunications infrastructure into the international conflict, but the available evidence does not support predictions of Scotland losing its internet simply because cables in the Persian Gulf are cut.
The more important Scottish question concerns the resilience of the networks already serving the country.
Recent failures in the Northern Isles show that the loss of a small number of connections can disrupt communications and essential services for days or weeks.
The UK Government has acknowledged the need for stronger protection of undersea infrastructure, while the Scottish Government has committed to examining another link to Shetland.
Those measures recognise a dependence that is becoming increasingly important as healthcare, commerce, transport and public services rely more heavily on digital systems.
Scotland’s most immediate vulnerability is not the small proportion of global internet traffic passing through the Strait of Hormuz. It is the possibility that communities and essential services remain dependent on infrastructure for which there is insufficient independent backup.
The Iranian warning underlines why that distinction matters. A country does not need to be directly attacked to experience the consequences of losing access to vital international services. Equally, a local cable failure can be serious without being part of any international conflict.
The measure of Scotland’s resilience will be whether its communications can continue when the infrastructure on which they depend is damaged.
Sources
Iran Has Detailed Plans to Hit Gulf Undersea Cables if War Resumes, Officials Say. Reuters, 23 October 2026. https://www.reuters.com/world/middle-east/iran-has-detailed-plans-hit-gulf-undersea-cables-if-war-resumes-officials-say-2026-10-23/
Iran’s Navy Says Three Tankers on Fire After Hitting Mines in Hormuz. Reuters, 14 November 2026. https://www.reuters.com/world/middle-east/irans-navy-says-oil-tanker-fire-after-hitting-mine-hormuz-2026-11-14/
Media Enquiries and Frequently Asked Questions: Strait of Hormuz and Submarine Telecommunications Cables. International Cable Protection Committee, 20 May 2026. https://iscpc.org/news/media-enquiries/
Critical Undersea Infrastructure Security and Resilience: Proposals for Modernising the UK’s Legislation. UK Government, 22 October 2026. https://www.gov.uk/government/consultations/proposals-for-new-legislation-to-strengthen-the-security-and-resilience-of-critical-undersea-infrastructure-cui/critical-undersea-infrastructure-security-and-resilience-proposals-for-modernising-the-uks-legislation-white-paper
Subsea Telecommunications Cables: Resilience and Crisis Preparedness. Joint Committee on the National Security Strategy, UK Parliament, 2025. https://publications.parliament.uk/pa/jt5901/jtselect/jtnatsec/723/report.html
National Risk Register 2026. Cabinet Office, 14 July 2026. https://www.gov.uk/government/publications/national-risk-register-2026
Meeting of the Scottish Parliament: Cyber Resilience Debate. Scottish Parliament Official Report, 8 October 2026. https://www.parliament.scot/chamber-and-committees/official-report/search-what-was-said-in-parliament/meeting-of-parliament-08-10-2026?iob=226305&meeting=20283
Programme for Government 2026–2031: Growing the Economy. Scottish Government, September 2026. https://www.gov.scot/publications/programme-government-2026-2031/pages/3/
Connected Nations 2025: Scotland Report. Ofcom, December 2025. https://www.ofcom.org.uk/siteassets/resources/documents/research-and-data/multi-sector/infrastructure-research/connected-nations-2025/connected-nations-2025-scotland-report.pdf
Outage Affecting Landlines, Mobile Phones and Internet – Shetland. Police Scotland, 20 October 2022. https://www.scotland.police.uk/what-s-happening/news/2022/october/outage-affecting-landlines-mobile-phones-and-internet-shetland/
