Hidden Lifelines: How Undersea Cables Shape Global Internet Connectivity

On September 6, 2025, a cable cut in the Red Sea disrupted internet connectivity across multiple countries, including India, Pakistan and the Middle East region.

On September 6, 2025, network monitoring company NetBlocks reported failures affecting two undersea cables systems: the South East Asia–Middle East–Western Europe 4 (SMW4) operated by Tata Communications, and the India-Middle East-Western Europe (IMEWE) managed by an Alcatel-Lucent consortium. These cuts led to significant internet outages and increased latency across parts of the Middle East and Asia, including India, Pakistan, and several Gulf nations.

The incident has raised concerns about the vulnerability of underwater information highways. This is particularly true given the ongoing conflict in the Red Sea region where Yemen’s Houthi rebels have been conducting a campaign targeting commercial shipping in response to the Israel-Hamas war in Gaza. 

Understanding Undersea Cable Technology

Despite advances in satellite internet technology, undersea cables still carry more than 99 percent of all intercontinental data traffic. Their dominance rests on two key advantages: far greater capacity and significantly lower latency. While satellites play an important role in providing emergency connectivity, they cannot match the scale and speed that submarine cables deliver to power the global economy. 

This dependence became clear during the recent Red Sea incident. When cable cuts disrupted services, Microsoft successfully rerouted traffic through alternative pathways. However, users still experienced delays because the longer rerouting paths increased the distance data had to travel. This underscored that even with backup systems, undersea cables remain the backbone of low-latency global connectivity. 

The reason undersea cables are so effective lies in their sophisticated engineering. Modern submarine cables contain bundles of fiber-optic strands—each no thicker than a human hair—sheathed in protective layers of plastic, steel, and copper to withstand deep-sea pressures and potential damage.

India’s Digital Vulnerability and Strategic Importance

This incident sheds light on India’s Underwater Domain Awareness (UDA). UDA refers to the capability of a nation or an organization to monitor, detect, and assess activities occurring beneath the surface of water bodies like oceans and seas. 

The need for UDA in India is crucial for national security and regional stability, as well as protecting critical infrastructure like submarine communication cables, which transmit over 95% of global internet traffic using the principle of total internal reflection through strands of glass or plastic fibers.

Concentrated Risk Points

The country hosts 17 international subsea cables across 14 landing stations. The majority of digital traffic flows through two key hubs: Mumbai and Chennai, which account for 68 percent of India’s data center capacity.

This concentration creates significant bottlenecks. A major incident affecting either location could impact a large portion of India’s international digital connectivity. Policy and Infrastructure Gaps

Despite heavy reliance on undersea cables, India lacks an indigenous cable repair fleet and depends on foreign vessels for repairs within its Exclusive Economic Zone. This dependency creates multiple vulnerabilities including delays due to complex permitting processes and security clearances for foreign vessels and crews.

Operational Challenges

India faces significant challenges in developing Unmanned Underwater Vehicles (UUVs) due to technological gaps, financial constraints, and operational difficulties. The country’s early-stage development of UUVs is hindered by poor performance of DRDO’s AIP system and Bharat Electronics Limited’s UUV, which has a 30-kilogram payload capacity, leading to import dependency. 

Financial constraints and operational difficulties are also exacerbated by India’s vast coastline, Chinese submarine incursions, seasonal monsoons, and fragmented inter-agency coordination.

India’s Response and Initiatives

Indigenous UDA Initiatives

India has launched several initiatives to strengthen its underwater surveillance capabilities. Indigenous development programs include the creation of UUVs like MAYA, AMOGH, and ADAMYA, which are enhancing naval surveillance capabilities. The Matsya 6000, a manned submersible, is being developed under the Samudrayaan project to further expand India’s deep-sea exploration abilities.

Infrastructure development includes the deployment of the Integrated Underwater Harbour Defence and Surveillance System (IUHDSS) in Port Blair, strengthening coastal security. India has also established international partnerships, particularly cooperation with the United States for co-developing autonomous undersea technologies and equipping MQ-9B Sea Guardian drones with sonobuoys for enhanced maritime surveillance.

India’s Cable Expansion Plans

India’s telecom players are pursuing new cable projects to enhance redundancy. Projects like the India Asia Xpress (IAX), India Europe Xpress (IEX), and the Africa cable system will expand capacity and diversify international routes.

Emerging opportunity involves discussions with Singapore to build a hybrid undersea cable carrying both high-speed data and solar energy. This dual-purpose infrastructure aligns with India’s “One Sun, One World, One Grid” initiative, positioning the country as a central node in a global green energy network.

To support these efforts, the Telecom Regulatory Authority of India (TRAI) has recommended policy incentives for the geographic dispersion of landing stations, reducing concentration risks. Further, TRAI has proposed classifying subsea cable infrastructure as an “essential service” under national security law, thereby ensuring legal protection and greater resilience for these critical assets.

Building Global Resilience

For India to secure its digital future, the country must develop indigenous repair capabilities to reduce dependence on foreign vessels for maintaining undersea cables. This includes investing in specialized cable repair ships and training skilled technicians who can respond to disruptions within India’s Exclusive Economic Zone.

Additionally, international collaboration remains essential for global internet connectivity security. India must enhance data sharing and standardize best practices through organizations like the International Cable Protection Committee. 

Investment in geographically diverse routes that bypass existing chokepoints like the Red Sea will reduce systemic risks to the global network. Coordinated efforts to address the aging repair fleet crisis require immediate attention, as two-thirds of maintenance vessels will reach end-of-life by 2040. 

Without collective action to fund new repair ships and training programs, the world faces a scenario where cable repair capacity cannot match the growing demand for new undersea cables.

Conclusion

The Red Sea cable cuts serve as a warning that our digital world remains vulnerable to physical disruption. As global data demand continues escalating and geopolitical tensions intensify, undersea cables and internet connectivity infrastructure require attention and investment.

For nations like India, with expanding digital economies, the stakes are high. The concentration of infrastructure in few locations, combined with dependence on foreign repair capabilities, presents vulnerabilities that demand strategic response.

The future of global internet connectivity depends not just on building new undersea cables, but on creating resilient, diverse, and secure networks capable of withstanding both accidental damage and attacks. Only through investment in infrastructure, indigenous capabilities, and international cooperation can we ensure that the digital lifelines powering our interconnected world remain secure and reliable.

Master Digital Age Governance & Technology Trends with VisionIAS Comprehensive Current Affairs →

Visit the Mains Corner and elevate your UPSC Mains 2025 preparation.

---

Undersea Cables FAQs

1. What percentage of global internet traffic travels through undersea cables?

Ans. Over 99 percent.

2. What causes most undersea cable damage?

Ans. Fishing equipment and ship anchors.

3. How many international undersea cables connect to India?

Ans. 17 cables across 14 landing stations.

4. Which Indian cities handle most international data traffic?

Ans. Mumbai and Chennai.

5. What technology allows multiple data streams in one undersea cable?

Ans. Dense Wavelength Division Multiplexing (DWDM).