The Internet Beneath The Strait: Why Iran’s Cable Threat Matters Beyond The Gulf

Iran’s Islamic Revolutionary Guard Corps (IRGC) has warned that undersea internet cables in the Strait of Hormuz could become targets if Iranian infrastructure comes under attack, raising the prospect of a conflict disrupting critical communications networks across the Gulf.

On Wednesday, IRGC political deputy Brigadier General Yadollah Javani said Iran could target seven major internet cables beneath the strait. Two senior Iranian security officials subsequently told Reuters on Friday that Tehran had drawn up detailed plans to target undersea communications cables if the United States and Israel launched renewed attacks. One official said Iran could seek to prevent repairs to prolong disruptions.

The officials, who spoke anonymously, provided few details about how or where attacks might take place. Their account has not been substantiated by a publicly available Iranian operational plan. The public warnings nevertheless highlight the vulnerability of infrastructure that carries international communications, financial transactions and cloud computing services.

Submarine cables carry more than 99% of the world’s internet traffic, according to the International Telecommunication Union (ITU). But the Strait of Hormuz accounts for less than 1% of global international bandwidth, according to TeleGeography research director Alan Mauldin, cited by Reuters. The distinction matters: damage could severely disrupt connectivity across parts of the Gulf without bringing down the global internet.

How Do Undersea Cables Work?

Submarine internet cables are made up of optical fibres that transmit data as pulses of light. The information travels through thin glass strands at high speed, carrying everything from messages and video calls to financial transactions and data exchanged between cloud servers.

The cables run along the seabed, connecting landing stations in different countries. At these stations, international traffic passes into terrestrial telecommunications networks, which route data to internet service providers, businesses, data centres and individual users.

Long-distance systems also use optical repeaters installed at intervals along the cable to compensate for signal loss and maintain transmission over thousands of kilometres. Cables contain protective layers designed to withstand environmental conditions and physical damage, with heavier armouring generally used in shallower waters where anchors and fishing activity pose greater risks.

These systems form an interconnected network rather than a collection of isolated links. A cable may connect two landing stations directly, while other systems provide alternative routes through different countries. Operators use network-routing arrangements to send traffic along available paths when a connection fails.

That redundancy is central to the internet’s resilience, however, it does not guarantee that all services will continue without disruption when multiple links are damaged. The outcome depends on the number of functioning routes, their capacity and how networks are configured.

Why Does The Strait Of Hormuz Matter?

The Strait of Hormuz separates Iran and Oman, linking the Gulf to the Gulf of Oman and the Arabian Sea. It is a critical passage for energy shipments, but it also forms part of the region’s international telecommunications infrastructure.

Several submarine cable systems connect Gulf countries to one another and to wider networks linking Europe, Asia and other markets. Javani’s warning referred to seven major cables beneath the strait, although that figure is the Iranian official’s claim rather than an independently established count in the public announcement.

The region’s importance also reflects the Gulf states’ growing dependence on digital services. Governments and businesses rely on international connectivity for financial transactions, cloud computing, data exchange and communications. Gulf countries have also invested in data centres and artificial intelligence infrastructure as part of efforts to diversify their economies beyond oil.

Iran’s warning comes amid wider threats against US-linked digital infrastructure in the region. Iranian security official Mohsen Rezaei had warned that data centres and artificial intelligence facilities could be targeted in a renewed conflict. Iranian strikes in March directly hit two Amazon Web Services facilities in the United Arab Emirates and damaged infrastructure near another facility in Bahrain, according to Reuters.

The strategic value of the cables lies in the disruption they could cause. A cut would not necessarily interrupt every connection, but attacks on several routes could reduce regional capacity and increase pressure on the remaining networks.

What Happens If A Cable Is Cut?

A damaged cable does not automatically disconnect a country from the internet. Network operators can reroute traffic through other submarine systems or available land-based connections. If those alternatives have sufficient capacity, much of the traffic may continue to flow with limited disruption.

The problem becomes more serious when several cables are damaged at once or when alternative routes cannot accommodate the additional traffic. Networks can become congested, leading to slower connections, higher latency and intermittent service. Particular destinations or services may become difficult to reach if the routes connecting them are affected.

The consequences could extend to financial services. Banks, payment providers and trading systems depend on reliable international data connections. Cloud computing, e-commerce and business communications also rely on links between data centres and users across countries.

A disruption could therefore affect particular transactions or digital services even if most internet users remain connected. The impact would depend on where cables were cut, which routes failed and how much spare capacity remained elsewhere in the network.

The ITU’s July 2026 report on submarine cable resilience identifies geographical concentration, physical risks and dependence on a limited number of cable systems as important vulnerabilities. It recommends greater route diversity, stronger monitoring and improved arrangements for restoring connections after damage.

Why Can Repairs Take Weeks?

Repairing a submarine cable is a specialised marine operation. Operators first have to identify and locate the fault through monitoring systems and testing. A suitable cable-repair ship must then be mobilised to reach the site.

The vessel locates and retrieves the damaged section from the seabed, cuts away the faulty portion and connects replacement cable. Technicians splice the optical fibres, restore the protective structure and test the repaired link before it returns to service.

The time required depends on the location and depth of the fault, the damage involved, weather conditions and the availability of repair vessels. A fault in deep water can require more complicated recovery work than one closer to shore.

The ITU’s technical guidance estimates a mean repair time of one to three weeks for a submarine cable fault. This is an estimate, not a guaranteed deadline. It can take longer if a repair vessel is unavailable or if access and operating permissions are delayed.

Conflict can complicate the process further. Higher insurance costs, security risks and delays in obtaining permission to enter territorial waters may prevent repair crews from reaching damaged infrastructure promptly. Reuters reported that one of the Iranian security officials said Tehran would seek to prevent repairs following an attack to extend communications disruption.

That allegation is significant because the duration of an outage can matter as much as the initial damage. Even where alternative routes keep some traffic flowing, prolonged repairs can leave networks operating with reduced capacity and less protection against further faults.

Could The Global Internet Go Dark?

A large-scale disruption in the Gulf would not automatically produce a global internet outage. The region accounts for a limited share of global international bandwidth passing through the Strait of Hormuz, and traffic can move along alternative submarine and terrestrial routes.

The more immediate risk would be to regional connectivity and services that depend on the affected links. Multiple cuts could disrupt financial transactions, cloud computing and e-commerce, particularly if the remaining routes lacked sufficient capacity or repairs were delayed.

There are also alternative corridors. Reuters cited analysts who said the Red Sea could represent a more consequential target for international traffic, carrying data between Europe, East Africa and Asia. However, Tehran has not publicly announced plans to target cables there.

Gulf states and technology companies have been investing in additional infrastructure to improve resilience. The ITU has also called for better coordination between governments and operators, faster repair procedures and greater geographical diversity in cable routes. Such measures cannot eliminate the risk of deliberate damage, but they can reduce dependence on individual links.

Iran’s warning therefore points to a vulnerability rather than a certainty of disruption. Undersea cables are essential to global communications, but the consequences of damage depend on the affected routes, the availability of alternatives and the time needed to restore service. A coordinated attack combined with delayed repairs could turn damage to a small part of the network into a prolonged regional problem, even if the wider internet remains operational.