On the other side of the world, the captain of the Chinese-owned ship Hong Tai was convicted by a court in Taiwan of severing an undersea telecommunications cable in February 2025 and sentenced to three years in prison in June 2025. The island democracy’s legislature later amended its laws to increase penalties for intentional damage to undersea cables or pipelines and allow for up to seven years in prison.
This year has seen several notable incidents involving both overt and covert threats to undersea infrastructure, including Iranian efforts to impose fees on operators of undersea cables running through the contested Strait of Hormuz. Separately, a joint operation involving the UK, Norway and the United States confronted Russian submarines that were practicing using a new technology to disable undersea cables in Arctic waters near Norway’s Svalbard archipelago.
What happens when the Internet’s undersea backbone, not to mention crucial energy infrastructure, is no longer protected by near-universal international agreement? Ars spoke with Braw to find out more. (The interview has been condensed and edited for clarity.)
Elisabeth Braw is the author of the book Undersea War.
Credit:
Hachette Book Group (cover art) / Annabel Moeller (author photo)
Ars Technica: Right now there’s so much suspicion and tension around undersea infrastructure. But it does seem like for quite a few decades, even during the Cold War, there was a broad international framework that mostly worked where countries generally agreed not to mess around too much.
Braw: Exactly. It worked for so long, and that’s why it’s so frightening to see that system that really depends on everybody doing the right thing and being a good seabed citizen, as it were, may not work for that much longer.
Ars Technica: I know it’s not really any single factor, but I’m curious what you would highlight as the key contributing factors to why we’re seeing a breakdown in that general agreement.
Braw: If you think about the absolutely crucial nature of subsea cables and pipelines, especially subsea cables… if they were to be disrupted for even just a minute, it would cause massive disruption to not just the New York City area, but also New York as a financial hub. It would cause operational losses, but also the loss of all that money that goes through the cables every second of every day.
So if you think about the utter importance of subsea cables to modern societies and modern economies, then that makes them incredibly attractive as a target. Whereas during the Cold War, we had telephone cables, but there weren’t that many of them, and we didn’t use them as much. Yes, they were used for international phone calls, and there were also telegraph messages that could be sent. But nobody sent telegrams around the clock, and nobody made international phone calls around the clock. So they were there, but they were just less crucial.