In September 2025, multiple undersea cables in the Red Sea were cut, causing significant Internet disruptions across Asia and the Middle East. The four major subsea cable systems affected included the South East Asia-Middle East-Western Europe 4 (SMW4), India-Middle East-Western Europe (IMEWE), FALCON GCX, and the Europe-India Gateway. Countries including India, Pakistan, Saudi Arabia, Kuwait, Qatar, and the United Arab Emirates (UAE) experienced slower Internet speeds and higher latency. (Latency refers to the time a data packet takes to travel from one point to another and back.)
Significance of Undersea Cables in Global Connectivity
Undersea cables are an essential component of modern communication systems. These cables, also known as submarine cables, are laid across ocean floors and are responsible for carrying most of the world’s data traffic. They transfer digital information in the form of binary code using light pulses through fibre-optic strands. This data could include text, voice, images, and videos, moving between data centres and end-user devices via a complex system of towers, servers, and cables.
Fibre-optic cables, now the global standard for undersea communication, are made of glass or plastic strands, protected by multiple layers of material such as polyethylene, copper, steel, and petroleum jelly. The transmission occurs through total internal reflection within the fibre, meaning the light signals are continuously reflected inside the core and do not escape. These cables offer high-speed data transfer with minimal signal loss often exceeding 400 Gbps per fibre pair. The introduction of these cables has enabled near-instantaneous digital communication across continents, forming the backbone of the global Internet.
While satellites and land-based cables further play important roles in communication, undersea cables handle the vast majority (around 99 per cent) of international data transfers. Depending on depth and risk factors, these cables are laid directly on the ocean floor or buried beneath it. In deeper waters, they are typically laid directly on the seabed due to reduced chances of disruption from human activity.
Immediate Impact of Cable Cut
Although it typically stays under one second globally, variations between domestic and international traffic could be noticeable, especially during activities like video conferencing, stock trading, and real-time online services.
Data from Kentik (a US-based network observability, network monitoring, and anomaly detection company) show that latency between Europe and Mumbai, a major landing point for subsea cables in India, increased from approximately 110–150 milliseconds to 190–300 milliseconds, depending on the cloud service provider used for measurement. The data also reported that connectivity between India and European financial hubs such as Frankfurt and London was particularly affected.
NetBlocks, an organisation that monitors global Internet connectivity, reported that these outages degraded network performance in multiple regions. Additionally, Microsoft confirmed disruptions, noting that its Azure cloud services experienced increased latency for traffic routed through the Middle East. While services were eventually rerouted through alternative pathways, delays in data transfer persisted.
In India, major network providers such as Bharti Airtel, Reliance Jio Infocomm, Vodafone India, and Tata Communications were affected. Although there was no complete breakdown in connectivity, noticeable delays were observed in data traffic between India and Europe. Latency between Mumbai and European data centres increased significantly, and in some cases, doubling the usual response time. Indian corporate using cloud and SaaS platforms faced difficulties in day-to-day operations, particularly in IT-enabled services and financial trading sectors.
Historical Context and Technological Evolution
The history of undersea cables dates back to the 19th century. Early efforts focused on connecting neighbouring countries through short cable stretches.
In 1856, American businessman, Cyrus West Field, founded the Atlantic Telegraph Company, backed by investors from the US and British governments, to connect countries across the Atlantic. Early attempts failed due to cable breakages, weak signals, and poor waterproofing. India rubber proved ineffective until the sap of the Malaysian Palaquium gutta tree (gutta-percha) was used as insulation. A British surgeon in Asia sent samples to England, leading to its use in the first submarine cable between England and France in 1850.
In 1858, Field’s company laid a cable between Ireland and Canada, enabling a brief but historic message exchange between Queen Victoria and President James Buchanan. A more durable connection was finally achieved in 1865 using the massive ship ‘Great Eastern’ and over 4,100 km of new cable. Over the years, the technology evolved from simple telegraph lines to coaxial and later advanced fibre-optic cables capable of carrying vast volumes of data. Today, more than 500 undersea cables covering over 1.3 million km form the invisible backbone of global Internet infrastructure.
Strategic Importance of the Red Sea Route
The Red Sea is one of the most critical arteries for global digital connectivity. It serves as a narrow yet essential route for undersea cables that link Europe, Africa, and Asia. Nearly 15–17 per cent of the world’s Internet traffic passes through this region, making it highly significant for global communication. The cables converge at points such as Jeddah (Saudi Arabia), Suiz (Egypt), and Djibouti, before continuing towards the Indian Ocean.
The geopolitical importance of the Red Sea adds to the vulnerability of its cable infrastructure. Any disruption in this area could affect Internet connectivity across multiple continents. The concentration of cables in a relatively shallow and narrow stretch of water increases the likelihood of damage, whether accidental or deliberate. The Red Sea has also become a high-risk area due to ongoing geopolitical conflicts, including the Israel-Hamas war spillover, Houthi attacks on shipping lanes, and tensions between regional powers.
Rerouting and Network Resilience
Despite disruptions, widespread outages were largely avoided due to the existence of multiple cable landings in countries like India. These additional connections allowed telecommunications companies to reroute Internet traffic through less affected or alternate pathways. Although rerouting helped maintain overall connectivity, it introduced inefficiencies. Data had to travel through longer or suboptimal routes, resulting in increased latency and reduced throughput.
Cloud service providers, including Microsoft, adapted by redirecting traffic outside the affected region. While this strategy ensured continued service delivery, users experienced delays, especially in activities requiring real-time data exchange. Kentik reported that traffic rerouting often involved passing through alternative subsea cables that added 50–100 milliseconds extra latency to Europe-India routes.
Causes of and Speculation about the Damage
Initially, there was uncertainty about what had caused the cable cuts. However, subsequent reports suggested that a commercial vessel dragging its anchor was the most likely cause severing multiple cables near Jeddah, Saudi Arabia. This region is particularly susceptible to such incidents because it is shallow, congested with shipping traffic, and hosts multiple cable landings in close proximity.
Though speculation existed about possible sabotage linked to regional conflicts, no conclusive evidence emerged confirming deliberate attacks. The Houthis, a rebel group in Yemen, had previously been accused of targeting shipping and undersea infrastructure as part of their campaign related to the Israel-Hamas conflict. While they denied involvement, the timing of the incident raised concerns among governments and network operators.
Moammar al-Eryani, the information minister of Yemen’s internationally recognised government, issued a statement attributing the damage to escalating militant activity. He called on the international community to take stronger measures to protect undersea infrastructure. Analysts emphasised that even accidental damage in such geopolitically sensitive corridors can have disproportionate effects on global connectivity.
Complexities in Cable Repair and Restoration
Repairing undersea cables is a complex, resource-intensive, and time-consuming process. Several factors contribute to the delay. Only a few specialised companies in the world possess the expertise and equipment necessary to conduct deep-sea cable repairs. These operations require specially equipped ships, trained divers, and advanced technology.
The process involves
- locating the damaged section using sonar and other mapping technology
- lifting the severed cable to the ship’s deck
- splicing and testing the fibre-optic strands
- re-laying the cable on to the seabed.
The location and depth of damage influence repair time. Shallow waters allow easier access but are also more vulnerable to human activity such as anchoring and fishing. Deep waters present technical challenges that slow down repairs.
Moreover, external factors such as regional conflicts, security concerns, and poor weather conditions could delay the deployment of repair vessels. It is reported that repair vessels must sometimes wait for clearance from multiple governments and security authorities before operations. Experts estimate that full repairs may take several weeks or even months particularly when multiple systems are impacted simultaneously.
Broader Implications for India
The cable cuts highlighted a potential strategic vulnerability for India. Despite hosting multiple subsea cable landings, India’s international connectivity relies heavily on corridors passing through the Red Sea. Industry experts have emphasised the need for greater infrastructure diversification including
- development of alternate cable systems bypassing chokepoints, such as Bab-al-Mandab strait, where dozens of cables have to pass through to get from Asia to Europe.
- partnerships with other countries for shared network resilience.
- expansion of domestic landing stations and terrestrial backhaul infrastructure.
These measures aim to reduce the risk of bottlenecks and maintain stable international data flows during regional disruptions.
Global Ramifications and the Role of Big Tech Companies
The incident also drew attention to the evolving role of technology companies in owning and managing global Internet infrastructure. Firms like Meta, Google, and Microsoft have been increasingly investing in their own under-sea cable projects. This marks a shift from traditional telecom consortia models where telecom companies formed consortia to share ownership and responsibility.
This change has prompted debate among policymakers. On the one hand, involvement from large tech companies could accelerate deployment and maintenance of such infrastructure. On the other, it raises concerns about monopolistic control over essential communication networks.
Conclusion
The cable cuts in the Red Sea serve as a reminder of the fragility and importance of global Internet infrastructure. Although the impact was managed through rerouting and network redundancies, the event revealed critical vulnerabilities in a key communications corridor.
The incident has sparked renewed interest in strengthening digital resilience through infrastructure diversification, strategic planning, and international collaboration.
For countries like India, the incident even underscores importance of investing in multiple routes and expanding cable-landing capacity. As digital dependence grows, ensuring the stability and security of undersea cables would remain a top priority for governments, companies, and global organisations alike.
© Spectrum Books Pvt Ltd.
