In the early days of the pandemic, I began pondering the idea of healing. I stumbled upon a story about a cable repair vessel, the Leon Thevenin, which had attended to a cable break off the west coast of Africa. The cable, which had broken deep at sea, had caused an alarming and potentially fatal slowdown in internet connections in western and southern Africa.

The break seemed like a reasonable metaphor for our fractured times: The cable had snapped during an oceanic landslide precipitated by huge floods in the Congo River. It took the ship more than a month to find the rupture and complete the repair. The idea of a cable carrying all our data under the sea appeared to me, at the time, to be a touch anachronistic in this, our digital age. After all, everything on my computer seemed to live in the cloud.

Advertisements suggested that my phone shot its information upward, celestially, then bounced it back down to earth. My night sky was peppered with moving satellites. Even my printer was wireless. However, I was soon to learn that most of our information actually does move along the cold wet floors of our silent seas, and that the cables were far more vulnerable than I could have imagined. In fact, I — a virtual Luddite — was able, over the course of three years of research, to imagine a reasonable plan that could take down a good chunk of the world’s internet.

It is estimated that more than 95% of the world’s intercontinental information travels through underwater cables that are no bigger than the pipes at the back of your toilet. Within those cables there are tiny strands of fiber optic material, the width of an eyelash. The 500-plus working data cables in the world carry not only our emails and phone calls but also the majority of the world’s financial transactions, estimated to be worth $10 trillion a day. Of course, they also carry all our petty desires and inanities, the emojis, the porn, the TikToks, the data smog. They are, essentially, our technological umbilical cords.

The Elon Musks of the world might want us to believe that Starlink is the true wave of the future, but satellites are slower and considerably more expensive, and most experts say that we will be using underwater cable systems for at least the next three decades. Yet, the cables, like all of us, must break sometimes. Fishing trawlers can snag a wire. Dropped anchors from cruise ships can exact damage. An underwater earthquake or a landslide can snap the cable deep in the abyssal zone. Or, as has happened increasingly in the last year, they can be sabotaged by state actors and terrorists bent on disrupting the political, social and financial rhythms of an already turbulent world.

Historically, cables in Taiwan, Vietnam and Egypt have all been vulnerable to breakage and sabotage. Last year, the Houthi rebels in Yemen were accused of cutting three cables underneath the Red Sea. This January, the British defense secretary, John Healey, accused Russian ships of spying on the location of undersea communication and utility cables that connect Britain to the rest of the world. Chinese and Russian carriers have been accused of dragging anchor over fiber optic cables in the Baltic Sea, causing damage in Finland, Estonia, Germany and other NATO territories. All of this has, in essence, precipitated a Coldwater War. In 2023 the former Russian president and close Putin ally Dmitry Medvedev said that there were no longer any constraints “to prevent us from destroying the ocean floor cable communications of our enemies.”

Cables — often several of them bunched together — come into our shores via landing stations. These are essentially coastline buildings, in suburban areas. They appear like low-slung windowless bungalows. The landing stations generally have minimal security. Even in the New York area, the landing stations are protected by little more than a camera and sometimes a chain-link fence. During the pandemic, I was able to access a Long Island landing station and stand directly above the manhole cover where the cables came from across the Atlantic. With a crowbar I could have reached down and touched them, felt the pulse of the world’s information traveling through my fingertips.

But sabotage on a small level is never going to disrupt our vast information flow. One of the beauties of the internet is that it is self-healing, meaning that information, when blocked, just travels in a new direction. But a coordinated series of attacks on the landing stations, combined with some low-level sabotage at sea (an ingenious diver can fairly easily manage to cut a cable), augmented by some deep-sea sabotage (the severing of cables using ropes and cutting grapnels lowered from boats), could, in fact, bring the world economies to a screeching halt.

The idea of a global takedown may seem a little far-fetched to some, and the world is more at risk from fishing trawlers dropping anchor, but then again we didn’t anticipate airliners flying into skyscrapers back in the early part of the century. The next major 9/11 could possibly happen underwater, with a series of attacks that are simultaneously local and global. A few strategically placed boats, a handful of divers and a couple of on-land sabotage teams could send the world into a vicious tailspin.

The deep-sea sabotage is most worrying because it can take a repair boat several weeks to find a break and initiate a fix. The continent of Africa, for instance, relies on a small number of major cable systems running along its east and west coasts. If the cables are simultaneously severed, the whole continent could go down. And a breakdown can affect just about everywhere: If Africa or the Baltic Sea or the Philippines were to become isolated, the repercussions would be felt all over the globe.

Information can lead to liberation. But the control of it can also become a new form of colonization. Once upon a time, we had ships. Now we have fragile tubes. This is especially frightening in a world where no one nation seems to want to be the police anymore. The International Cable Protection Committee is an effective lobby, but it’s more a forum than a legislative organization. The task of repair nearly always falls to private businesses. The cables are owned by network operators (SubCom, Alcatel, Nippon Electric Co.), but increasingly content providers (Google, Amazon, Microsoft, Meta) are putting their money in cables to ensure the interconnection of their data centers.

We are connected, and wired to one another, but sometimes those connections can hang on a not-so-protected string. If a tech-challenged novelist can figure out a system of damage — and nothing I reveal here is beyond the fingertips of anyone — then perhaps it is time for us to reevaluate our systems, or at least be aware of what could unfold, or untangle.

Colum McCann is the author, most recently, of the novel “Twist.”