The Geopolitical Importance of Subsea Cables

When people think about global communications, they might think of satellites, miles above the Earth. But in fact the vast majority of the world’s telecommunications goes through hundreds of garden hose-sized fibre optic cables that run along the ocean floor. While most nations rely on these submarine cables for communications, they can fall foul of geopolitics and international tensions.  And things can get very difficult when they are damaged, cut or tampered with. 

January 08, 2023

Geopolitical Importance

Many countries rely heavily on submarine cables to help to keep their economy going and their security in check. 

“[The cables] carry 99 per cent of all transcontinental internet traffic. So that includes your video calls, your stock market transactions, conference calls, military operations — everything,” Joe Brock, a Singapore-based Reuters correspondent, tells ABC RN’s Late Night Live.

Though they cost hundreds of millions of dollars to build, they offer greater speed than satellite internet, which only accounts for a very small fraction of all internet traffic. 

“It’s much slower to transmit data through satellites, and there’s far less bandwidth.

These underwater cables have always been of interest to governments, says research analyst Lane Burdette.

“It’s because of how much governments rely on them from a communication standpoint.”

Burdette works with TeleGeography, a Washington-based company that collects and analyses communication data.

“Sub cables have always been important for geopolitics,” she says.

“However, I think the geopolitical situation of the last decade, especially in regard to potential seabed warfare, [has] ramped up.

“And so people are paying more attention to sub cables.” 

Lately, they’ve been the source of increased tension between the US and China, who have been in dispute over submarine cable deals.

For context, while there are some government-owned cables across the globe, the majority of cables are privately owned and operated by telecommunications companies.

Chinese company HMN Tech was set to build a submarine cable running from Singapore to France, but lost its contract after the US put in a higher bid of US$600 million ($944 million), Brock explains.

He says the US wanted to have more control over the security of their communications, hence their push to outbid the Chinese company.

“The US government intervened behind the scenes to persuade, with cash sweeteners, telecoms companies to change their mind and flip it and then choose an American supplier called SubCom, which is a main US cable supplier, and they do work for the US government,” he explains.

“The US would much rather cables were built by US companies … so it’s sort of this behind-the-scenes jostling and, in this case, Washington won the day.”

Spying and Cutting Ties

There are constant fears of espionage and sensitive data being extracted from submarine cables.

For example, Brock says US intelligence services “claim that the Chinese and others can fit back doors onto cables, which would reroute data … Your private data could then be hoovered up by intelligence services”.

The most likely way to hack data from a submarine cable is from the landing station, he says.

These land-based stations are where the cable connects with terrestrial networks.

They’ve been hacked before. Brock points to the case where Edward Snowden exposed that the US’s National Security Agency had tapped into submarine cables and was extracting data from US citizens, more than a decade ago.

What happens if cables get cut?

These fears are warranted. History has shown that cables have been cut before. 

And once a country’s communications has been cut off, they become more vulnerable.

For instance, during World War I, the British cut all of Germany’s undersea cables, except one.

“That’s how they were able to get the Zimmermann telegram, which, of course, was a rather important component of the war,” Burdette says.

In January 1917, the Zimmermann telegram was issued by the German Foreign Office proposing an alliance with Mexico if the US entered World War I.

British Intelligence got hold of this information and informed the Americans, which led the US to declare war on Germany.

“So these cables have been intentionally damaged in warfare before. They’re a really important way for states to be able to connect across the globe. And they’re an interesting target in the case of a hot conflict,” Burdette says.

However most of the damage to submarine cables isn’t intentional.

“I would say the biggest threat to sub cables out there, at least on a routine basis, is accidental interaction with people. So [for example] fishermen and trawlers — that comprises the majority of breaks,” she explains.

Natural disasters, such as earthquakes, also contribute to cables’ damage.

For example, Tonga was left largely offline for more than a month after a volcanic eruption in 2022 damaged its cable.

Taiwan also lost its internet during February 2023, and claimed that Chinese ships were responsible, Brock says.

“They didn’t say whether it was an intentional act. And the Chinese have not responded to explain whether they were involved … so there’s a bit of mystery that’s shrouded around that. 

“Taiwan is a big concern because there’s so much geopolitical tension over [that region]. They have several cables, they are all running through areas of water, which are highly contested,” Brock says.

“But I think it’s given warning to everyone … It shows what could be done if someone wants to do something deliberately.”


Let's have a chat

Learn how we helped 100 top brands gain success.