Australia’s digital lifeline under threat as undersea cable war intensifies

A Russian sabotage attack in the Baltic has sparked global alarm - and experts warn Australia’s digital lifelines are just as vulnerable, with 99 per cent of our data flowing through a mere 15 undersea cables, writes Ian Langford.

In the frozen Gulf of Finland, Russia’s undersea sabotage campaign is ramping up — and Australia risks sleepwalking into the same threat.

Fifteen thousand kilometres away, in the icy Gulf of Finland, Vladimir Putin is waging a silent war – and Australia is sleepwalking straight into the same trap.

Most Aussies wouldn’t give two hoots about what happens between Estonia and Finland. But when a Kremlin-linked ship sliced through the Estlink 2 power cable on Christmas Day 2024, it sent a clear message: Undersea sabotage is here, it’s real and it works.

That attack was just one of at least 11 on Europe’s critical seabed infrastructure in the past 15 months.

Estonia has begun naval patrols to protect an undersea cable supplying electricity from Finland following suspected sabotage. Picture: Jussi Nukari / Lehtikuva / AFP

NATO’s so worried it launched Operation Baltic Sentry to protect cables and pipelines. Why? Because they know what’s at stake.

Now consider this. Australia relies on just 15 undersea cables for 99 per cent of our international data traffic. Banking, hospitals, defence comms, airline bookings, Netflix binges – all of it flows through these wires. Cut a few cables, and Australia doesn’t just buffer, it blacks out.

If you think this is just doomsday talk, think again.

Chinese “research” ships have been lurking near our cables for years, mapping routes and testing defences. They’ve reportedly developed drones that can slice through cables 4km below the surface. Imagine that, a silent attack that cripples the nation without a single shot fired.

The Chinese ship Tan Suo Yi Hao was labelled a “spy ship” in April in media reports, with some expressing fear it could be gathering intelligence on Australia’s seabed cables. Picture: China’s Institute of Deep-sea Science and Engineering

And what have we done in response? Precious little. We need urgent action on three fronts.

First, build more cables and spread the risk. Why are we funnelling everything through Singapore and Guam? It’s strategic insanity. We should be laying cables direct to India, the Middle East and new Pacific routes – diversifying our digital lifelines before it’s too late.

Second, we must protect what we’ve got. That means deploying undersea surveillance drones, acoustic sensors, and naval patrols to monitor threats in real time. If NATO can do it in the Baltic, Australia can do it in our own backyard.

A map of the Indo-Pacific region showing shipping density and undersea cables between Australia and the region. Image: Supplied by Department of Defence

Third, build sovereign data centres here on home soil. Too much of our data lives overseas, exposed to foreign laws and prying eyes. Local data centres aren’t just an economic boon, they’re a security necessity. And they need to be spread across the country, not just clustered around Sydney and Melbourne where one flood could wipe them out.

Yes, this will cost money. But how much would it cost if an adversary cut us off tomorrow? Billions in economic losses, chaos in financial markets, hospitals scrambling, defence systems blinded. That’s not a risk, that’s national negligence.

Last century, oil fuelled the engines of power. Now it’s data, and we’re gambling with ours.

Australia needs to wake up. Undersea cables are the arteries of our nation. If we don’t defend them, we’re left open to an attack that could paralyse the country overnight.

The time for hand-wringing is over.

Our competitors see the digital domain as a battlefield. It’s time our leaders did too.

Brigadier Ian Langford (Retd) is a professor at the University of NSW

Originally published as Australia’s digital lifeline under threat as undersea cable war intensifies