The conflict between Iran and the US appears to have reached a stalemate. The US navy continues to prevent Iranian vessels or others transiting to or from Iranian ports. Iran, meanwhile, threatens shipping moving in or out of the Persian Gulf region via the Strait of Hormuz. Iran has also recently said it will establish a new “restricted zone” stretching into the Gulf from the Strait of Hormuz – although details remain sketchy.Less frequently discussed is the network of undersea cables across the Persian Gulf which connect the region with the outside world. On August 16, the Wall Street Journal reported that the Iranian government was considering attacks on that network. In the Gulf’s relatively shallow waters, threats to this critical undersea infrastructure (CUI) pose a credible risk to the Gulf States and the wider world.These cables form a largely unseen foundation of the global economy, carrying more than 95% of international data traffic. Their role extends far beyond everyday internet and call usage. They support financial transactions, government communications and the increasingly data-intensive operations of the global technology sector. Major technology companies such as Google, Amazon, Meta and Microsoft are investing heavily in subsea connectivity as they expand data-centre networks and seek to meet the growing demands of AI. For the Gulf States, where hundreds of billions of dollars are being invested in AI as part of efforts to diversify economies away from fossil fuels, disruption to this infrastructure could therefore have consequences far beyond communications. Cutting these CUI cables threatens a key element of their broader economic ambitions.To demonstrate the scale of this risk, the key cable networks include the Fibre in Gulf submarine cable system, which connects Bahrain, Iraq, Kuwait Oman, Qatar, Saudi Arabia and UAE. There is also the Falcon Network, which connects Bahrain, Egypt, India, Iraq, Kuwait, Maldives, Oman, Qatar, Saudi Arabia, Sri Lanka, Sudan and Yemen. The Asia-Africa-Europe1 (AEE1) network, with landing sites in Oman, Qatar, Saudi Arabia and UAE, linking southeast Asia to Europe via Egypt. And the Gulf Bridge International, which links Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, UAE, and has onward connectivity to India and Europe. Key undersea internet calbes are vulnerale to disruption in the Persian Gulf and Strait of Hormuz. TeleGeography, CC BY-NC-SA With that web of connections funnelled through the Strait of Hormuz, an international waterway that has long been of strategic importance for oil and gas has taken on a new significance as a choke point for global undersea infrastructure.What makes the Strait of Hormuz and the rest of the Gulf region particularly vulnerable to an attack on the CUI is the shallow water. With an average depth of 50 metres and a maximum depth of less than 100 metres, those who might wish to attack the CUI network do not need the sort of high-end capabilities of Russia’s Gugi agency. Gugi, which is the Russian acronym for the Main Directorate of Deep Sea Research, is responsible for underwater sabotage and espionage. Remotely operated vehicles (ROV) with working depths of thousands of metres are commonplace in the oil and gas industry. There are growing numbers of autonomous underwater vehicles (AUV) with similar operating parameters in that field. Both can be repurposed and used for offensive operations. Iran has already debuted its own mine clearance ROV, and there may be other capabilities which it has not chosen to publicise. The shallowness of the Persian Gulf puts most of it well within the depths military divers are able to operate at. We could also see the sort of blunt threat posed by a ship “accidentally” dragging its anchor to cut cables in the manner we have witnessed in the Baltic.So it’s entirely feasible that Iran could conduct attacks against the CUI network. And the threat has already affected planned extensions or new elements of this undersea infrastructure. Several projects have been put on hold after their owners or contractors declared they can’t safely operate in the Gulf. This neatly illustrates the impact of conflict on the ability to maintain and extend the cables carrying so much of the world’s trade and communication. In the context of the Middle East, that will have a direct impact on the ambitions of Gulf States to become AI-enabled economies.Iran clearly appreciates the strategic and operational significance of the regional CUI network and will have put significant effort into mapping it. It is also reasonable to assume that it will have a trained force of divers able to operate at depths that would enable them to reach the cables across the Persian Gulf seabed. We know that they have an ROV designed for mine clearance operations – and it’s highly likely operate other assets in support of a well-developed offshore oil industry. How far would Iran go?The most important question is what would the Iranians be prepared to do? An attack on the cable network could create a very significant impact on trade and communications across the Middle East, with global ramifications. Such an attack would need to be targeted and limited if Iran wished to avoid global condemnation. But it’s a risk they may be willing to take given their current isolation. That “maybe-they-would” doubt leads us to consider a new form of deterrence – of one nation’s ability to affect either CUI of another, or of broader networks. It’s something of an extension of Nixon’s madman theory of nuclear deterrence. A nation that is desperate enough could be willing to take extreme action in the CUI domain – with what might appear to a rational observer to be disproportionate regional and potentially global consequences – in order to deter more traditional military strikes against it.To a certain extent this should come as no surprise. The CUI network is the cyber age equivalent of the roads, bridges and rail systems which have long been targets for military planners seeking to disrupt an opponents’ ability and willingness to fight. Iran’s capacity and desire to conduct this sort of operation may be uncertain – but that very ambiguity may prove enough to have a significant impact on the region.John Aitken does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.