Sabotage at sea, Europe’s energy under attack

You have probably heard the phrase: “We are in the middle of a war over energy” in discussions about prices, subsidies and fuel supply security. But recent events in the Baltic and North Seas have given this statement a new and more concerning meaning. We are in the midst of a hybrid war.  

Fortunately, this conflict has not yet resulted in human casualties, so we should use the word “war” carefully. However, Prussian general Carl von Clausewitz defined war as the use of violent force “to compel our opponent to fulfil our will”. While this conflict lacks direct lethality towards humans, significant damage is already occurring – just not on land, but at sea.  Why the sea?

First, much of this activity takes place outside territorial waters, which complicates diplomatic responses. If such incidents happened within a country’s jurisdiction, they could trigger official diplomatic actions – or worse. The second reason is that the sea provides a perfect environment for covert operations. Monitoring activities on the water’s surface is difficult, tracking airspace above it is only slightly easier, and observing what happens beneath the waves is nearly impossible. This creates an ideal setting for undetected sabotage, where the damage is often only discovered after the fact – just as we saw with the Nord Stream 1 & 2 pipeline explosions on 26 September 2022.

Interconnector damage

Another critical factor is the vulnerability of trading routes outside territorial waters. These are busy corridors for cargo ships, fishing fleets, and research vessels. Maritime choke points are known for occasional accidents – but in recent months, the number of such “accidents” has surged, particularly those involving lost or dragging anchors near energy infrastructure. Recent incidents include:

• October 2023: The Balticconnector natural gas pipeline was damaged by an anchor from a Chinese vessel.  

• December 2024: Finnish authorities seized the oil tanker Eagle S, suspecting the crew had deliberately dragged an anchor to damage the 650 MW Estlink 2 power cable, which has been offline ever since.  

• Recently: The Norwegian Coast Guard intercepted the KV Bison, a Norwegian-flagged vessel en route from St. Petersburg to Murmansk, on suspicion of involvement in the sabotage of a fibre-optic cable between Latvia and Sweden.

Journalistic investigations have also uncovered suspicious patterns in the movements of fishery and research vessels near offshore wind farms and interconnecting power cables. While no direct damage has been reported yet, it is clear that these activities involve mapping the exact locations of critical infrastructure – preparations, not coincidences.  Are we ready for escalation? 

Interconnectors serve a crucial role, primarily by facilitating the exchange of energy between countries. While no single interconnector is vital for the security of supply, smaller countries with limited backup capacity are far more vulnerable to disruptions. This is particularly true for natural gas supply in the Baltic region, where alternative sources are scarce.  

For electricity, every interconnector matters. Fortunately, most countries today can still meet their domestic needs, but vulnerabilities remain. Norway, for instance, has taken a cautious approach, with its government not only blocking new interconnectors but also viewing them as a risk due to the price volatility they introduce. However, history shows that Norway itself needed to import power in 2003 and 2004 following consecutive dry years that reduced hydroelectric output. A damaged interconnector might not pose an immediate crisis, but in the long run, it weakens a nation’s security of supply.  

The same applies to Germany. Despite being well-connected to neighbouring power markets, Germany’s reliance on imported electricity will grow after its coal phase-out by 2038. Offshore wind power is set to become the backbone of Germany’s energy transition, making wind farms and their connecting cables increasingly critical infrastructure. Without sufficient backup power, any disruption to offshore wind generation could have significant consequences.

The hybrid war on energy infrastructure is already underway, and we must prepare for further disruptions rather than assume they won’t happen. Clausewitz reminds us to judge our opponents by their actions, not by how we wish them to behave. If recent events are any indication, the threats to Europe’s energy security are no longer hypothetical – they are happening in real-time.

This article originally appeared as a column on montelnews.com