Governments around the world are asking critical questions about national security and submarine cables, seeking to protect this critical infrastructure and mitigate risk.
In the minds of many, threats from bad actors are a top concern, despite the fact that the vast majority of cable faults are caused by accidents from fishing and anchor drags.
On November 20, 2025, members of the U.S. House Committee on Homeland Security convened a hearing to discuss foreign adversary threats to subsea cable infrastructure. TeleGeography's Chief Research Officer Tim Stronge testified at this joint hearing for the Subcommittee on Transportation and Maritime Security and the Subcommittee on Cybersecurity and Infrastructure Protection.
Watch Tim's congressional testimony below and read the report he submitted to Congress.
Chairmen, Ranking Members, and distinguished members of the committee. Thank you for the opportunity to speak with you today.
My name is Tim Stronge, and I am the Chief Research Officer at TeleGeography. We provide the independent data that the global communications industry relies on to map and measure the internet.
I am here today to talk about the physical backbone of the modern U.S. economy: submarine fiber-optic cables. The strategic importance of this network boils down to three characteristics: these cables are vulnerable, they are critical, and they are irreplaceable.
First, vulnerability. I’ve brought a cable sample with me. Encased inside are thin strands of glass, each about the width of a human hair.
If this looks fragile to you, that’s because it is. Individual cables are especially vulnerable to damage from fishing gear and anchor drags. The global network experiences roughly 200 faults every year—an average of four per week.
Second, criticality. My son Kaz is away at college in Connecticut. One of our favorite ways to stay connected is to share funny videos. Fiber-optic networks make that possible. Perhaps you already lay awake at night, worrying about how we must protect our nation’s strategic reserve of cat videos. But even if not, it’s important to understand that cables carry far more than social media and web content.
They are the backbone of global finance. More than $12 trillion in financial transactions flow over these cables each day. Millions of American jobs now depend on access to digital infrastructure. The U.S. government, itself, is heavily reliant on commercial submarine cables.
Third, irreplaceability. A common misconception is that satellites are a viable one-for-one replacement. They are not. Satellites are a vital emergency backup for mission-essential use, but they cannot replace the sheer capacity and cost-efficiency of fiber. Cables carry over 99% of all intercontinental data for a simple reason: the cost-per-unit of cable capacity is 2,800 times cheaper than satellites.
Collectively, these three conditions—physical vulnerability, high criticality and irreplaceability—might seem like a scary mix.
But I am here today with good news. For a cable operator, the loss of revenue streams during downtime is financially catastrophic. That means that these private companies are already powerfully self-incentivized to secure their cables.
Let's return to that vulnerability. The vast majority of those 200 annual faults are accidents. This constant threat has compelled the private sector to invest billions of dollars in a tangible, layered defense.
Companies have built dozens of new cables and geographically diverse landing stations to ensure data always has a backup path. Cable operators are innovating with new detection technology that uses the fiber itself to sense threats. And they have funded a global fleet of two dozen repair vessels on 24/7 standby.
Crucially, the strategies built to defend against routine accidents will also help to secure the network against malicious attacks.
However, there are critical gaps where government action is needed:
The industry has already demonstrated its deep commitment to cable security. It looks to government as a partner to help clear the path.
Thank you, and I look forward to your questions.