Undersea cables, the critical infrastructure that carries up to 99 percent of international data and communications traffic, are increasingly recognized as vulnerable targets amid evolving geopolitical tensions. Stretching hundreds of thousands of kilometers beneath the world’s oceans, these fiber optic cables form the invisible backbone of modern life, facilitating everything from financial transactions to streaming entertainment. However, their physical fragility and strategic importance have made them focal points in contemporary hybrid warfare and security concerns.
One such landing station is located in Liguria, northern Italy, where the India Europe Xpress cable, majority-owned by India’s Reliance Jio Infocomm and China Mobile, connects data centers in Milan with regions extending through Crete, Saudi Arabia, Djibouti, Oman, India, and onwards to Singapore. Despite its significance, local workers remain largely unaware of the building’s purpose, highlighting how hidden and overlooked these installations often are.
There are currently over 600 undersea cables either in operation or planned globally, with an estimated 1.7 million kilometers deployed as of 2025. The longest cable, circling Africa, measures approximately 45,000 kilometers, and technology companies like Meta are planning cables extending up to 50,000 kilometers to facilitate global connectivity. Historically, the undersea cable industry played a major financial role, with Britain dominating much of the 19th-century market due to access to materials like guttapercha, used for insulation.
Security challenges for these cables date back to their earliest use. In 1914, a British naval assault destroyed German cables shortly after the onset of World War I, significantly hampering German communications. More recently, incidents have raised alarms: dragging anchors from Chinese or Russian-linked vessels have severed cables and pipelines in regions like the Baltic Sea and near Taiwan. While affected ships often claim these disruptions were accidental, the lack of jurisdiction beyond 12 nautical miles from a country’s coast makes enforcement difficult.
A 2023 incident involving a Chinese-linked ship cutting two cables and disabling the Balticconnector gas pipeline connecting Estonia and Finland was interpreted by some analysts as an intentional geopolitical warning. Such “accidents,” alongside the 2022 explosions on the Nord Stream pipeline, have heightened awareness among defense officials in NATO countries. Since Finland and Sweden joined the alliance, NATO has expanded efforts to monitor cable sites in vulnerable maritime regions.
Emerging technologies, including sensors attachable to cables and submarine detection tools, are being explored to defend against sabotage, though cost and operational challenges remain. The industry itself relies on a limited number of cable-laying and repair vessels—fewer than 80 worldwide—with around 150 to 200 cable faults occurring annually, mostly caused accidentally by fishing activities or anchors.
Tensions also extend to the undersea mining of polymetallic nodules, which contain critical minerals like manganese, iron, and cobalt. Licenses granted by the United States in international waters have raised concerns about potential underwater conflicts between mining companies, potentially involving drone technology.
Further complicating security prospects, there are calls from some hardline outlets near Tehran advocating for disruption of cables in strategic choke points such as the Strait of Hormuz, though questions remain regarding the feasibility and repair capabilities amid ongoing conflicts.
The vulnerability of undersea cables poses a significant strategic concern, especially for countries like Ireland, which sit outside NATO and host many transatlantic cables connecting Europe with the Americas. While satellites can offer backup connectivity, their capacity is insufficient to replace the vast data flows carried by subsea cables.
As geopolitical competition intensifies beneath the waves, experts argue that understanding and protecting this critical maritime infrastructure is essential to maintaining global stability and the uninterrupted functioning of the digital economy.