Beyond their technical function, undersea cables hold immense strategic importance, influencing power dynamics among nations. Control over these networks can grant countries significant advantages in intelligence gathering, economic leverage, and military operations. The ability to monitor or disrupt data flows through these cables can provide strategic insights or hinder an adversary's capabilities, making them pivotal assets in the geopolitical landscape. In recent years, concerns over the security of these cables have grown as major powers recognise their value.

Recent incidents have highlighted the vulnerabilities of undersea cables to both accidental damage and deliberate sabotage. In November 2024, two submarine telecommunication cables, the BCS East-West Interlink and C-Lion1, were disrupted in the Baltic Sea. These near-simultaneous incidents prompted accusations from European officials and North Atlantic Treaty Organization (NATO) member States of potential hybrid warfare and sabotage. Similarly, in February 2024, four cables the AAE-1, Seacom, EIG, and TGN systems were severed in the Red Sea near Yemen, disrupting internet services to over 100 million people across West and North Africa and affecting 70% of data traffic between Europe and Asia. These incidents underscore the susceptibility of submarine cables to hostile actions, which could have cascading effects on global communications and economies.

The Indo-Pacific region, characterised by dynamic economic growth and strategic significance, heavily depends on undersea cables for connectivity. Countries such as Japan, Australia, and Singapore serve as major hubs in the global submarine cable network, making the security of these cables crucial not only for national interests but also for regional and global stability. The region's political complexities, including territorial disputes and the presence of major global powers, further amplify the importance of safeguarding this infrastructure. China’s growing investments in undersea cable projects, including its Digital Silk Road initiative, have raised concerns among Indo-Pacific nations about potential vulnerabilities and control over data transmission. As a countermeasure, the Quadrilateral Security Dialogue (Quad) comprising the US, Japan, Australia, and India has prioritised undersea cable security, allocating over $140 million to projects in the Pacific. This initiative focuses on supporting new undersea cables and providing cybersecurity capacity-building and technical assistance to secure the region’s infrastructure.

Recognising the critical importance of securing undersea infrastructure, international alliances like NATO have also initiated measures to enhance the protection and resilience of these networks. In May 2024, NATO launched a new Maritime Centre for the Security of Critical Undersea Infrastructure within its Maritime Command in the UK. This initiative aims to bolster the security of undersea cables and pipelines by implementing new tools to monitor potential threats and enhance infrastructure protection. Similarly, the European Union has proposed an emergency fleet dedicated to rapid cable repairs, reflecting growing concerns about intentional disruptions to these vital networks.

Several companies play pivotal roles in the undersea cable industry, contributing to the construction, maintenance, and operation of these critical infrastructures. Key players include Alcatel Submarine Networks (France), SubCom, LLC (US), NEC Corporation (Japan), NEXANS (France), Prysmian Group (Italy), HENGTONG GROUP CO., LTD. (China), ZTT (China), NKT A/S (Denmark), Corning Incorporated (US), Hellenic Cables (Greece), Sumitomo Electric Industries, Ltd. (Japan), and Apar Industries (India). These companies are instrumental in advancing the technology and expanding the global reach of submarine cables, ensuring the robustness and efficiency of international communications. However, the industry has also become a battleground for geopolitical competition, as Western nations seek to reduce reliance on Chinese-built infrastructure due to security concerns.

Despite these measures, legal and regulatory frameworks for protecting undersea cables remain inadequate. The United Nations Convention on the Law of the Sea (UNCLOS) provides some legal protections, but enforcement mechanisms are weak, and there is little clarity on how to respond to deliberate attacks or espionage. Unlike nuclear or space treaties, there is no comprehensive global agreement dedicated to securing undersea communication infrastructure. This legal gap creates opportunities for geopolitical manoeuvering, allowing states to exploit ambiguities without facing direct consequences. Countries are now exploring new agreements and cooperative frameworks to enhance the resilience of submarine cable networks, but progress remains slow.

As the world continues to become more digitally interconnected, the significance of undersea cables will only increase. Ensuring their security requires a comprehensive approach involving diplomatic cooperation, technological advancements, and strategic investments in redundancy measures such as satellite-based communication networks. While satellites can complement undersea cables, they cannot replace them due to their lower data capacity and higher latency. Thus, safeguarding these critical networks must remain a priority for governments and private stakeholders alike.

In the 21st century, global power will not only be determined by military strength, economic might, or territorial control but also by the ability to secure and dominate digital infrastructure. The cables running along the ocean floor, once overlooked, are now central to geopolitical competition. How nations manage this evolving challenge will determine the stability of international communications, the resilience of the global economy, and the security of critical national infrastructure. Ignoring their importance in an era where information is power would be a costly mistake, leaving nations vulnerable to both economic and security threats.

This article is authored by Gunwant Singh, scholar, international relations and security studies, Jawaharlal Nehru University, New Delhi.