R. Vignesh
IT WAS WIDELY reported on March 23 that Iran threatened to target undersea internet cables in the Red Sea region. This development was reminiscent of the threats issued by the Houthi rebels in Yemen in early 2024, when they launched a sustained campaign targeting merchant ships passing through the Red Sea. Last September, several countries across West Asia and South Asia, including India, experienced significant internet disruptions owing to damage to undersea cables in the region. Although the International Cable Protection Committee (ICPC) attributed the cuts to accidental causes, suspicion of Houthi involvement in potential acts of subversion persists.
Against this backdrop, Iran’s targeting of merchant vessels in the Strait of Hormuz, which has already elevated concerns over a global energy crisis, suggests that any deliberate attack on undersea cable networks in the Red Sea has the potential to cause major disruptions to internet traffic. This evolving dimension of the West Asia crisis shifts the spotlight to the depths of the oceans, where vast networks of undersea cables are increasingly becoming targets of subversion.
Around 99 per cent of global internet traffic passes through a vast network of about 500 undersea cables spanning more than 1.7 million square kilometers. These networks have virtually become the nerve centre of the information-driven globalised world. However, this very dependence has made them susceptible to sabotage and grey-zone warfare. Their vulnerability is evident from the growing instances of damage to undersea cables, especially in maritime regions that are either near zones of armed conflict or are theatres of territorial contestation or geopolitical competition. This is particularly evident from the increasing instances of damage to undersea cables in regions such as the Taiwan Strait, the Baltic Sea and the Red Sea over recent years.
There are essentially three factors that make undersea cables easy targets for grey-zone warfare. First, the unprotected and ungoverned nature of the high seas, where much of these cable networks are located, makes it easy for malicious actors to damage them. Second, they can be damaged with relative ease by employing rudimentary tactics, such as using a commercial vessel to drag its anchor over the cables. Third, malicious actors can carry out such actions with anonymity and deniability, as these cables are mostly located in remote locations and are vulnerable to accidental damage by regular shipping activity.
NATO’s Operation Baltic Sentry, launched in January 2025, presents a viable operational template for protecting undersea cables against acts of subversion on the high seas. This operation involves the navies of seven European countries, which have collectively deployed warships and other naval assets in the Baltic Sea with a mandate to secure undersea cables in the region. This deployment serves three key objectives. First, it aims to deter malicious actors by establishing a visible naval presence along key Sea Lanes of Communication (SLOCs). Second, it seeks to establish sustained monitoring of the region through multi-layered surveillance using various naval assets, including warships, aircraft, submarines and maritime drones. Third, it facilitates information sharing and data collation among the participating navies, thereby collectively enhancing their Maritime Domain Awareness (MDA) and Underwater Domain Awareness (UDA).
Operation Baltic Sentry, however, also demonstrates how securing undersea cables can be a highly resource- and technology-intensive effort involving multiple naval platforms and advanced surveillance technologies. It is here that the advent of new-age maritime technologies, such as Autonomous Surface Vehicles (ASVs) and Autonomous Underwater Vehicles (AUVs), can play a crucial role. Operation Baltic Sentry, as well as the UK’s Atlantic Bastion Programme launched in December, has been extensively utilising these technologies to continuously monitor undersea cables and pipelines.
At India’s first International Subsea Cable Systems Conference in Delhi last year, the chairman of the Telecom Regulatory Authority of India (TRAI) highlighted the need to rapidly expand the country’s undersea cable infrastructure to meet its growing data demands. In this context, envisaging robust operational and policy frameworks to protect these cables becomes imperative for safeguarding India’s critical data infrastructure.
India can assume a leadership role in partnering with other key stakeholders in the Indian Ocean to pool naval resources and technical capabilities to secure undersea cables in the region. While this can serve as a deterrence strategy akin to Operation Baltic Sentry, India must also initiate efforts to build greater resilience in this domain. This includes the acquisition of dedicated cable-laying and repair vessels, which India currently lacks and for which it relies on foreign ships to undertake repairs.
In March 2025, China unveiled a powerful deep-sea cable-cutting device, raising concerns among several nations, including India. This device underscored how such technologies could enable nations to discreetly damage critical undersea cables and thereby disrupt global communications. Iran’s latest threats, if true, also have the potential to cause wide-ranging internet disruptions affecting many nations, including India. These developments are indicative of the urgent need to protect undersea cables in an increasingly tumultuous global environment.
Vignesh is associate fellow with the Military Affairs Centre at the Manohar Parrikar Institute for Defence Studies and Analyses (MP-IDSA).