Iran’s Threat to the Undersea Internet: Could the World Be Disconnected? Suspicious Ships, Submarine Cables and the Possibility of a Digital Catastrophe

The next major escalation in the Iran war may not begin with missiles striking oil installations or military bases. It could begin quietly, beneath the surface of the sea, where thousands of kilometres of fibre-optic cables carry the communications upon which modern civilisation depends. Reports of Iranian-linked vessels behaving suspiciously near important submarine internet cables have raised the possibility that Tehran is preparing an unconventional response to renewed American and Israeli military attacks. The evidence does not establish that sabotage is underway, but the threat is sufficiently serious to deserve attention.

According to reporting by the Financial Times, maritime intelligence company Windward identified at least four Iranian-linked vessels making unusual movements near submarine cable routes in the Gulf of Oman during October 2026. Three were tankers subject to American sanctions, while the fourth was an Iranian fishing-support vessel. The ships reportedly slowed, changed direction, lingered near cable corridors and, in some cases, temporarily ceased transmitting their automatic identification signals.

Such behaviour is not proof of hostile activity. Ships can alter course, stop or disable tracking equipment for numerous reasons, and the precise intentions of the vessels remain unknown. Nevertheless, the movements have attracted attention because they coincide with explicit Iranian warnings that submarine communications infrastructure could become a target if the United States and Israel resume major attacks.

In October, senior Iranian security officials reportedly told Reuters that Tehran had developed plans to attack undersea communications cables in the Gulf in the event of renewed warfare. Iranian Revolutionary Guard representatives have also publicly referred to the cables passing through the Strait of Hormuz, warning that the region's digital infrastructure would not necessarily remain untouched if Iran itself came under attack.

The combination of threatening statements and unusual maritime activity is more concerning than either development considered separately. It suggests that submarine communications infrastructure has entered the strategic calculations surrounding the conflict. Whether Iran intends to act upon those threats, or merely wishes to demonstrate that it possesses additional means of retaliation, remains uncertain.

But could Iran actually disrupt the international internet by attacking submarine cables? The answer is yes, at least on a regional scale. Undersea fibre-optic cables are physical infrastructure, and like other infrastructure they can be damaged or destroyed. Their vulnerability is not theoretical. Accidental cable damage occurs regularly around the world, most commonly through fishing activity and ships' anchors, while earthquakes and other natural events occasionally produce more extensive disruptions.

The International Telecommunication Union estimates that submarine cables carry more than 99 per cent of intercontinental data traffic. Despite the popular impression that global communications depend principally upon satellites, the enormous volume of information moving between continents travels through fibre-optic connections laid across the ocean floor.

These cables support international banking, commercial transactions, government communications, scientific research, cloud computing, video services and countless ordinary internet activities. Modern economies have become so dependent upon this infrastructure that serious interruptions can affect services far removed from the immediate location of a damaged cable.

The Strait of Hormuz presents a particular vulnerability because several important cable systems pass through a relatively confined maritime region. Iraq, Kuwait, Bahrain and Qatar depend heavily upon submarine connections through this area for their international communications. Damage affecting several systems could therefore produce substantial disruption across the Gulf.

The consequences would depend upon which connections were lost, how much alternative capacity remained available and how quickly network operators could redirect traffic. The internet was developed with considerable capacity to route communications around failures, and the loss of one cable does not normally produce a general collapse. But alternative routes have finite capacity, and simultaneous failures can overwhelm available redundancy.

The problem becomes more serious during wartime. Repairing damaged submarine cables requires specialised ships, equipment and personnel. Such operations may be delayed by military activity, maritime restrictions, insurance difficulties and the danger to civilian repair crews. A cable failure that might be repaired relatively quickly in peacetime could become a prolonged disruption if the surrounding waters were an active conflict zone.

This is where the possibility of deliberate sabotage becomes especially troubling. An attacker seeking to cause economic disruption would not necessarily need to disconnect an entire continent. Damage to several important regional connections, combined with conditions that prevented prompt repairs, could create a communications emergency lasting far longer than an ordinary technical outage.

Imagine the consequences for a major financial centre such as Dubai, Doha or Manama if international connectivity were severely degraded for an extended period. Banks might experience delays in international payments and settlement instructions. Businesses dependent upon overseas cloud services could find essential applications unavailable or unreliable. Airlines, shipping companies and logistics operators could encounter difficulties coordinating activities across borders.

Hospitals and emergency services would not necessarily cease functioning, since many critical systems possess local capabilities and alternative communications arrangements. Nevertheless, disruptions to remote records, specialist consultations, supply chains and communications with outside organisations could complicate operations precisely when wartime pressures were already increasing.

The economic effects could spread through international markets. Financial institutions depend upon reliable data transmission, and uncertainty over the availability of communications infrastructure can itself undermine confidence. Traders and investors might respond to a regional communications crisis by reducing exposure, delaying transactions or moving assets to perceived safer locations.

There is also the possibility of a psychological effect disproportionate to the physical damage. The knowledge that an adversary could threaten the infrastructure of a modern digital economy might generate anxiety among businesses and governments even before substantial disruption occurred. Cybersecurity specialists have long recognised that attacks upon critical infrastructure can be intended not merely to destroy equipment but to influence political decisions by creating fear and uncertainty.

For Iran, such a strategy would carry considerable risks. Damage to regional communications infrastructure would affect neighbouring countries as well as American and Israeli interests. Gulf states whose economies depend upon international finance, energy exports and digital commerce would have strong reasons to condemn attacks against their telecommunications systems. Iran could therefore inflict economic damage while simultaneously alienating governments whose neutrality or diplomatic cooperation might otherwise be valuable.

There is also an important distinction between damaging the regional internet and destroying the global internet. Although submarine cables carry most international traffic, the world's communications network is geographically extensive and contains numerous alternative routes. The Strait of Hormuz accounts for only a small proportion of global international bandwidth, according to telecommunications analysts. Even the destruction of several cables there would not automatically disconnect Europe, North America, Australia and Asia from one another.

The more realistic danger is a serious regional outage accompanied by wider economic disruption. The internet elsewhere would continue functioning, although some international services could experience congestion, increased delays or temporary interruptions as traffic was redirected.

The worst-case scenario, however, involves a much broader conflict in which submarine cable damage occurs alongside attacks upon other infrastructure. Suppose that renewed American and Israeli strikes against Iran produce retaliation against Gulf energy facilities, ports, communications networks and regional military installations. At the same time, important submarine connections suffer damage, while maritime hostilities prevent repair vessels from operating safely.

Under such conditions, the effects could reinforce one another. Energy disruptions could interfere with transportation and industry, while degraded communications would complicate the management of the emergency. Financial institutions might struggle with international transactions, businesses could face delays in obtaining essential supplies, and governments would need to coordinate their responses under increasingly difficult circumstances.

If the conflict expanded further, involving attacks against communications infrastructure outside the Gulf, the consequences could become more serious still. Multiple geographically separated cable failures could reduce the ability of network operators to redirect traffic, creating regional isolation and severe international congestion.

This would not necessarily mean the complete disappearance of the internet. Domestic networks, locally hosted websites, cached information and some terrestrial or satellite connections could continue operating. But the distinction between an internet that technically survives and one that remains sufficiently reliable for modern economic life is important.

A badly degraded international communications system could produce substantial economic losses without requiring the total destruction of the network. Many modern businesses operate on the assumption that overseas servers, payment systems, communications platforms and supply chains will remain continuously accessible. Remove that assumption, even temporarily, and the fragility of highly interconnected economic arrangements becomes apparent.

Australia should pay attention to this possibility. Our geographical isolation makes submarine communications infrastructure particularly important. Australia possesses multiple international cable connections, principally linking the continent with Asia, North America and neighbouring Pacific countries. This provides substantial resilience, but it does not eliminate dependence upon physical infrastructure vulnerable to accidents, natural disasters and deliberate interference.

An attack confined to the Strait of Hormuz would not automatically sever Australia's international connections. Nevertheless, disruption to Gulf financial markets, energy infrastructure and global shipping could affect Australian businesses and households. A wider campaign against submarine communications networks would raise more direct questions about Australia's own connectivity and economic security.

The Royal Australian Navy has recognised the growing strategic importance of subsea infrastructure, including the risks posed by sabotage and hostile interference. The issue is no longer confined to telecommunications engineers. It has become part of national security planning because modern military operations and civilian economies depend upon networks that are difficult to protect continuously across vast stretches of ocean.

The problem illustrates a broader weakness of technological civilisation. The more efficient and interconnected our systems become, the greater the consequences when important connections fail. Globalisation has reduced costs and increased convenience, but it has also created dependencies that ordinary citizens rarely consider.

A supermarket can accept electronic payments from millions of customers because communications networks, financial institutions and electricity systems operate together. An international business can coordinate production across several continents because data moves almost instantaneously between offices, factories and warehouses. Governments can administer essential services because information systems remain available.

These arrangements work remarkably well under normal conditions. Their weakness becomes apparent when several supporting systems experience disruption simultaneously.

This does not mean that society is one damaged cable away from collapse. Such claims exaggerate the danger and underestimate the considerable resilience built into modern telecommunications networks. But it does mean that national preparedness should include the possibility of prolonged communications failures, particularly during major international conflicts.

Governments should encourage greater geographical diversity in international cable routes, strengthen cooperation with telecommunications operators and maintain realistic plans for restoring essential communications during emergencies. Businesses should examine whether critical operations can continue when overseas services become temporarily unavailable. Financial institutions and emergency services require arrangements that do not depend entirely upon uninterrupted access to a single communications provider or international network.

Ordinary households also have reasons to maintain modest emergency preparations. Some cash, essential supplies, access to important telephone numbers and locally stored copies of necessary documents can reduce dependence upon digital systems during temporary disruptions. These precautions are useful for ordinary power failures, floods and storms, quite apart from the possibility of wartime sabotage.

There is a significant difference between fearmongering and recognising a genuine vulnerability. The former treats every suspicious development as proof that disaster is inevitable. The latter asks whether the threat is technically possible, whether a potential adversary has expressed an intention to exploit it, and what the consequences would be if the threat were carried out.

In the present case, the answers justify concern. Submarine cables can be damaged, Iran has threatened them, and a major regional conflict could make repairs difficult. What remains unproven is whether the particular vessels identified near the cable corridors were engaged in hostile preparations.

The larger lesson is that modern warfare increasingly threatens the civilian infrastructure upon which entire societies depend. Energy facilities, telecommunications networks, financial systems and transportation links are no longer peripheral to international conflict. They can become instruments of strategic pressure, with consequences extending far beyond the immediate battlefield.

The disturbing thought is that the modern world has placed so much of its economic and social life upon systems that most people never see, buried beneath oceans thousands of kilometres away. We rarely think about those cables because they usually work. Their importance would become painfully obvious if they suddenly stopped working.

A major war in the Middle East could remind us that the digital world, for all its apparent sophistication, ultimately depends upon remarkably vulnerable physical connections. The internet may seem almost immaterial, but its foundations are made of glass, metal and machinery resting on the ocean floor. That is a vulnerability no serious government can afford to ignore.

https://www.zerohedge.com/geopolitical/why-were-iranian-linked-ships-lingering-over-worlds-undersea-internet-cables