How Global Internet Access Relies on A Few Hundred Vulnerable Undersea Cables – Guy D. McCardle

In an era where digital connectivity is the backbone of global communication and commerce, the infrastructure that supports this vast network remains largely out of sight and, unfortunately, out of mind. Admiral James Stavridis, former NATO Supreme Allied Commander, succinctly highlighted this oversight when he said: 

“If you ask people what the internet runs on, most will say satellites. But it actually runs on less than 500—not millions, not tens of thousands—undersea cables embedded in the deepest parts of the sea. These cables are a point of immense vulnerability.”

The Backbone Beneath the Waves

Most people assume that satellites power the internet, but the truth is far different. The vast majority of global communication, including internet traffic, flows through undersea cables. These submarine fiber-optic cables carry about 97% of global data, making them the backbone of the modern internet.

The undersea cable network is a vast web of hundreds of cables stretching over 1.4 million kilometers along the ocean floor. These cables connect nearly every country on Earth, ensuring that information flows seamlessly between continents. Everything from emails and web pages to financial transactions and video calls relies on this hidden infrastructure.

The importance of undersea cables cannot be overstated. They handle an astonishing amount of international data, enabling instant communication across the globe. These cables also boast immense capacity, transmitting multiple terabits of data per second. Without them, the modern digital world would grind to a halt, affecting businesses, governments, and everyday internet users.

Satellites might seem like the obvious solution for global communication, but they have limitations. Undersea cables are much faster, offering significantly lower latency. They also provide vastly superior bandwidth, meaning they can handle more data at a time. Reliability is another factor—while satellites are vulnerable to weather and technical issues, undersea cables are generally more dependable. While satellites have their place, they cannot match the scale and efficiency of submarine cables.

Our reliance on undersea cables is only increasing. Tech giants like Amazon, Google, Meta, and Microsoft now control nearly half of the world’s undersea bandwidth. This highlights the critical role these cables play in powering the global digital economy. Every day, they ensure the smooth operation of international trade, communication, and innovation.

Despite their importance, undersea cables are vulnerable. Accidental damage from fishing activities and ship anchors accounts for most cable faults, but intentional sabotage is an even bigger concern. Recent incidents, such as damages to cables in the Red Sea, have shown just how exposed this infrastructure can be. These vulnerabilities could disrupt global communication and commerce, highlighting the need for greater investment in their protection.