YoIt was early 2022, after a massive volcanic eruption, when Tonga was plunged into darkness. The underwater eruption, 1,000 times more powerful than the bomb dropped on Hiroshima, sent tsunami waves rippling across the nearby Tonga archipelago and blanketed the island’s white coral sands in ash.
The force of the Hunga-Tonga-Hunga-Ha’apai eruption cut off internet connectivity to Tonga, causing a communications blackout just as a crisis was unfolding.
When service was restored weeks later to the undersea cable that provides the country with internet, the scale of the disruption became clear. The lack of connectivity had hampered recovery efforts while devastating local businesses and finances, many of which rely on remittances from abroad.
The disaster exposed extreme vulnerabilities in the infrastructure that underpins the functioning of the Internet.
Contemporary life is really inseparable from a functioning Internet, says Nicole Starosielski, a professor at the University of California, Berkeley and author of The Undersea Network.
In that sense, it is very similar to drinking water, a resource that sustains our existence. And, like water, very few people understand what it takes to get it from a distant reservoir to the tap in our kitchen.
Modern consumers have come to imagine the Internet as something invisible in the atmosphere — an invisible “cloud” just above our heads, raining down data on us. Because our devices aren’t tethered to any wires, many of us think everything is wireless, Starosielski says, but the reality is far more extraordinary.
Almost all internet traffic — including Zoom calls, movie streams, emails and social media — reaches us via high-speed optical fibres strung across the ocean floor. These are the veins of the modern world, stretching nearly 1.5 million kilometres beneath the sea and connecting countries via physical cables that funnel the internet through them.
Starosielski explains via WhatsApp that the data transmitted by his voice travels from his mobile phone to a nearby cell tower. “It’s basically the only wireless hop in the entire system,” he says.
From the cell tower, it will pass through a set of terrestrial fibre optic cables, travelling at the speed of light underground. It will then go to a cable landing station, usually somewhere near water, and from there to the bottom of the seabed, before arriving at a cable landing station in Australia, from where the Guardian is speaking to Starosielski.
“Our voices are literally at the bottom of the ocean,” he says.
Spies, sabotage and sharks
The fact that the data that powers financial, government and some military communications travels over cables no thicker than a hose and protected by little more than the seawater that covers them has become a cause for concern for lawmakers around the world in recent years.
In 2017, NATO officials reported that Russian submarines had stepped up surveillance of internet cables in the North Atlantic, and in 2018, the Trump administration sanctioned a Russian company that had allegedly provided “submarine capabilities” to Moscow to monitor its undersea network.
A Russian attack on undersea cables would cause “significant damage to our economy and our daily lives,” said Jim Langevin, a member of the US House Armed Services Committee.
Attacking internet cables is a long-standing weapon in Russia’s hybrid warfare arsenal. When Russia annexed Crimea in 2014, Moscow cut the main cable connection to the peninsula, allowing it to take control of its internet infrastructure and spread disinformation.
Global conflicts have also been shown to have unintended disruptive effects on Internet cable systems. In February, Iranian-backed Houthi militants attacked a cargo ship in the Red Sea. The sinking of the Rubymar was likely responsible for the severing of three undersea cables in the region, disrupting a significant portion of Internet traffic between Asia and Europe.
The United States and its allies have also expressed deep concern about the potential for their adversaries to access undersea cables to obtain “personal information, data, and communications.” A 2022 Congressional report on the topic highlighted the growing potential for Russia or China to access undersea cable systems.
This is a method of spying that the United States is very familiar with: in 2013, The Guardian newspaper revealed that the UK’s GCHQ had tapped into the internet cable network to gain access to vast amounts of communications between completely innocent people and specific suspects. This information was then passed on to the NSA.
The documents, revealed by whistleblower Edward Snowden, also showed that an undersea cable connecting Australia and New Zealand to the United States was tapped to allow the NSA to access Australian and New Zealand internet data.
Despite the array of dangers and increasingly strong warnings from Western governments, calls for greater action to secure the cable network have largely gone unheeded and many consider the threats exaggerated.
“There are no publicly available and verified reports indicating deliberate attacks on the cable network by any actor, be it Russia, China or a non-state group,” a 2022 EU report states.
“This arguably implies that the threat scenarios being discussed may be exaggerated.”
An expert who spoke to the Guardian was more blunt in his assessment, describing the sabotage threat as “nonsense”.
The data confirms this, showing that sharks, anchors and fishing pose a greater threat to the global Internet infrastructure than Russian spies. A US report on the subject showed that the main threats to the network are “accidental incidents involving human beings”. On average, a cable is cut “every three days”.
“In 2017, an undersea telecommunications cable was accidentally severed by a ship off the coast of Somalia, leading to a three-week internet outage that cost the country $10 million per day,” the report said.
An unequal Internet
For many experts, however, the biggest risk to the Internet is not sabotage, espionage or even fraudulent presenters, but the uneven distribution of the cable infrastructure that spans the globe, linking the world’s digital networks.
“There are no cables everywhere,” Starosielski says. “There is a concentration in the North Atlantic connecting the United States and Europe, but there are not as many in the South Atlantic.”
“So you can see that some parts of the world have a high level of connectivity… and diversity in terms of having multiple routes in case there is a disruption.”
In 2023 there were more than 500 communications cables on the ocean floor, but a quick look at The map of the world’s submarine cable networks shows that they are largely concentrated in economic and population centers.
The uneven distribution of cables is most apparent in the Pacific, where a territory like Guam, with a population of just 170,000 and home to a US naval base, has more than 10 internet cables connecting the island. New Zealand, with more than five million inhabitants, has seven. Tonga has just one.
In the wake of the 2022 eruption in Tonga, governments around the world were spurred into action, commissioning reports into the vulnerabilities of the existing undersea cable network, while technology companies worked to harden networks and ensure such an event could not happen again.
Last month, internet service in Tonga failed again.
Large parts of the country were left in the dark after the undersea internet cable connecting the island’s network was damaged, causing chaos for local businesses.
For now, economic fundamentals favor building more cables across the Western world and in emerging markets, where digital demand is booming. Despite warnings of sabotage or accidental damage, experts say that without a market imperative to build more resilient networks, the real risk is that places like Tonga will remain unavailable, jeopardizing the very promise of digital equity on which the Internet was founded.