Shadow fleets and ‘grey-zone' sabotage: The communication battleground beneath the waves

Sydney Morning Herald

21-06-2025

In October 2023, damage to the Balticconnector gas pipeline and telecom cables linking Estonia, Sweden and Finland made headlines. Official statements were cautious, but satellite data later tracked a Chinese-flagged vessel suspiciously close to the damage zone. A similar pattern repeated off the coast of Denmark's Bornholm island just months later. Each time, attribution proved elusive – but not implausible.
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CSRI executive director Andrew Yeh said the involvement of commercial shadow fleets was consistent with grey-zone doctrine.
'Undersea cables underpin prosperity and security in the digital age,' he said. 'We cannot afford to be naive about the unprecedented threat that China and Russia's grey-zone operations pose to the UK's undersea infrastructure.
The Baltic Sea is a peculiar theatre for modern maritime competition. At first glance, it's a crowded body of water – shallow, narrow, hemmed in by nine countries, six of them NATO members. But that congestion is precisely what makes it a high-stakes flashpoint. It has become a transport lifeline for Vladimir Putin's Russia, both in terms of exports and imports, and strategically.
About 60 undersea cable systems crisscross the Baltic, with more added each year. These cables don't just power Netflix in Norway or Zoom in Zeebrugge – they form the encrypted foundation of NATO's command networks, trans-Atlantic data flows, and even the control systems for power grids and offshore wind farms.
Yet NATO admits that it can't see everything. Much of the Baltic's maritime domain isn't covered by the automatic identification system that tracks commercial ships. Vessels operating 'dark' – without beacons, under false flags or masking their activity – have found freedom in the grey.
That's where Task Force X comes in.
Onboard Alliance, we're watching unmanned surface vehicles such as the Saildrone Explorer and Martac's Devil Ray glide in formation with crewed vessels. These aren't science-fair toys. They're the spear point of a NATO-wide effort to fill the surveillance gaps in increasingly contested waters.
This week in The Hague, the issue will be high on the agenda of world leaders as they come together to discuss and debate European security and, in particular, the rate of spending needed to keep the continent safe.
Data from the new systems and unmanned vehicles taking part in these exercises will be fed directly to a screen in real-time during the summit, showcasing the technology's effectiveness in enhancing NATO's understanding of the Baltic region.
Leaders will also be asked to endorse a new rapid adoption action plan to ensure NATO's defences remain fit for purpose in an era of rapidly evolving threats and disruptive technological advancements.
Task Force X is designed to integrate uncrewed systems – surface, subsurface and aerial – into NATO's maritime task groups. It's a lesson in agility, drawn from the US Navy's successful experiments in the Persian Gulf and Red Sea.
But where those missions focused on anti-terrorism and anti-piracy, this one is squarely about deterring sabotage, especially to undersea infrastructure. The recent spate of attacks has accelerated the mission's rollout, with several NATO nations contributing commercial off-the-shelf systems upgraded with AI detection, sonar arrays and encrypted communications.
'The idea is to decentralise detection,' says Captain David Portal of Allied Maritime Command. 'We use autonomous vessels to track anomalies – dark ships, unexpected activity around known cable routes – and then feed that data into a real-time, pan-alliance picture.'
The goal? To spot suspicious activity before the cable is cut – not after.
What makes this different from past NATO initiatives is its scope. Task Force X isn't just plugging in new drones – it's part of a broader 'digital ocean vision', which seeks to use AI, big data and machine learning to create a living, learning map of NATO waters.
Simon Purton, the head of innovation at NATO's Allied Command Transformation, says the organisation has moved with unprecedented speed following the disruptions to undersea infrastructure in the past year, integrating the allies' capabilities with scalable platforms to provide situational awareness, and deterrence, 24/7.
'The future that we see for the military exists in our industry ... in academia ... in our science and technology labs,' he says. 'So what we're trying to do then is create some tangible delivery on that, and also make sure that things are operationally relevant.'
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Onboard the ship Alliance, that transformation is tangible. In the ship's command centre, researchers and officers watch sonar feeds and machine-learning-driven anomaly alerts. On-screen blips mark every commercial vessel. More worrying are the gaps – ship tracks that go dark near critical cable corridors, only to reappear hours later, far from where they should be.
The stakes aren't abstract. In January, foreign ministers from Finland, Estonia, Latvia and Lithuania issued a joint communique pledging to 'intensify maritime patrols' after more confirmed sabotage incidents. While none pointed fingers directly, the language was unequivocal: this was the work of hostile actors.
Russia, for its part, denies involvement. But few NATO commanders are buying that narrative.
Australia's vast digital economy, worth billions of dollars, relies almost entirely on a surprisingly small and vulnerable network: just 15 known international subsea cables. These vital conduits, stretching to international hubs such as Singapore and Hawaii, carry 99 per cent of the nation's data traffic.
It is one of the many reasons NATO is working with its 'Indo-Pacific 4' partners – Australia, Japan, South Korea and New Zealand.
A NATO official tells me that the need to protect critical undersea infrastructure is a 'topic of increasing concern' in both the Euro-Atlantic and the Indo-Pacific.
'For this reason, we are sharing information and best practices about how we are going about it,' the official says. 'We also see potential for co-operation ... specifically in the area of technology development to allow us to better survey our critical undersea infrastructure.'
With its blend of national contributions and off-the-shelf tech, the exercises are designed to deter further mischief, not through confrontation, but through visibility. The thinking is simple: if you can be seen, you can be deterred.
Still, Task Force X is not without challenges. As with any move towards automation, there are questions around command authority, cyber vulnerabilities and even the ethics of allowing AI to classify potential threats.
But few aboard Alliance seem bogged down in philosophical hand-wringing. The pace of experimentation is brisk. The political appetite, sharpened by recent attacks, is real.
As I disembark under a steely Nordic sky, one thing is clear: the front lines of conflict are no longer just on land, sea or air. They are digital, invisible and, increasingly, underwater.