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When the Baltic became a battlefield: Why we added a land-based alternative to our backbone

2026-01-21

Between November 2024 and January 2025, the Baltic Sea shifted from a stable digital corridor to a site of hybrid warfare. At least eight critical undersea cables, essential for communications and financial transactions, were deliberately severed in a coordinated campaign. This event has fundamentally changed our approach to digital infrastructure security.

While governments respond and competitors reassess their vulnerabilities, we are communicating from a position of resilience. Our investment in a fully terrestrial fiber route through Scandinavia between our Finland and Sweden data centers was a proactive measure, not a reaction.

What actually happened

On November 17-18, 2024, two cables were cut within 24 hours of each other. Maritime tracking placed a Chinese bulk carrier at both locations at precisely the time damage occurred. Swedish analyst @Auonsson calculated a 1 in 10,000 to 100,000 years chance that all eight breaks were coincidental.
 
On Christmas Day, the most significant incident occurred. The tanker Eagle S, part of Russia’s “shadow fleet,” damaged the Estlink 2 power cable and four telecommunications cables, leaving anchor drag marks nearly 100 kilometers long along the seabed.
 
German Defense Minister Boris Pistorius was blunt: “No one believes these cables were cut accidentally.”
The Eagle S departed from Russia’s Ust-Luga port, dragged its anchor for nearly 100 kilometers across the Gulf of Finland seabed, damaging the Estlink 2 power cable and four telecommunications cables before Finnish special forces intercepted the vessel on December 26, 2024.

The hidden success story

Finland seized the Eagle S. Sweden opened sabotage investigations. NATO announced Baltic Sentry, a dedicated surveillance mission.
 
Importantly, consumer service disruptions were minimal. Traffic was rerouted, and services continued without major interruption.
 
This outcome was possible because redundancy was effective. As Estonia’s Ministry of Justice confirmed: “Estonia’s connections remain sufficiently backed up via other sea and land cables, guaranteeing ongoing operation of all services.” This reflects sound engineering, not chance.

The fragile infrastructure we all depend on

Undersea cables carry 99% of intercontinental internet traffic and $10 trillion in daily financial transactions. However, they are highly vulnerable, measuring only 25mm in diameter and resting unprotected on the seabed.
 
In the Atlantic, attacking these cables requires deep-sea capabilities. In the Baltic, where the average depth is only 55 meters, attacks are easier. (Baltic Sea, 2025) As Dr. Sidharth Kaushal explained, “much simpler tools—things like dragging an anchor—are perfectly feasible means of attack.”
 
Rear Admiral (Ret.) Mike Studeman connected the global pattern: “The six sea cables more than likely cut by Russia and China since November 2024… shows you what can happen.”

Why we went overland

At the end of 2025, we completed a fully terrestrial fiber route connecting our data centers in Finland and Sweden. This route runs entirely through Scandinavia, without crossing any sea, and is engineered to withstand scenarios like those recently experienced in the Baltic.
This decision was based on anticipation, not reaction.
 
We recognized the strategic vulnerabilities of Baltic Sea cables, shallow waters, global conflicts, and the rise of hybrid warfare tactics. We chose not to leave our customers’ connectivity dependent on infrastructure susceptible to such risks.
 
Terrestrial fiber offers decisive advantages:
  • Accessibility: Technicians can reach damage points quickly—no specialized ships or diving equipment
  • Lower attack surface: Not exposed to maritime sabotage or dragging anchors
  • Physical security: Access points can be monitored and secured
  • Routing flexibility: Simpler to establish multiple varied routes
We own and operate our entire MPLS-based backbone across Sweden, Finland, and major European points of presence. This provides end-to-end control, eliminates third-party dependencies, and avoids delays associated with undersea repairs.

Endurance that actually works

Our investment in terrestrial routes is part of a broader philosophy. In December 2025, we announced a major backbone upgrade with Smartoptics, implementing IP-over-DWDM with 400ZR+ coherent optics.
 
When the southern submarine routes via Estonia were severed on December 30th, traffic was immediately rerouted. The graphs below illustrate this: one route drops to zero, and traffic shifts seamlessly to our other redundant paths. There were no outages, and the network functioned as designed.
When the submarine cable route failed, traffic on that path stopped immediately.
At the same time, traffic was rerouted through one of our three other redundant paths, ensuring business continuity.

The strategic reality

Carnegie Endowment analysts warned that adversaries use cable sabotage “as a low-cost way of unnerving societies below the threshold of a complete outage.” The goal isn’t a blackout; it’s to demonstrate vulnerability and create uncertainty.
 
The EU has responded with new policies, but policy implementation takes time, and infrastructure development takes even longer. International political tensions, however, can escalate rapidly.
 
We operate in an environment where nation-states target the physical layer of our digital economy. The organizations that thrive will be those that took infrastructure robustness seriously before it became a crisis.

What this means for your business

If your business depends on reliable connectivity, the key question is not whether your provider uses submarine cables, but whether they have effective alternatives if those cables fail.
 
Glesys provides robust, stress-tested infrastructure designed to address current geopolitical risks. Our backbone is redundant in practical ways that ensure continuity, even in the event of significant disruptions such as anchor damage in the Baltic.
 
We do not simply react to infrastructure crises. We anticipate them, invest proactively, and build solutions that perform reliably when others may not.
 
The Baltic incidents elevated the vulnerability of undersea cables from a theoretical threat to an operational reality. NATO is now permanently patrolling these waters. European governments are revising their critical infrastructure frameworks. Every serious infrastructure provider is reassessing their exposure.
Eric Löwgren
About the author
Eric Löwgren is Head of Network at Glesys, responsible for the design, stability, and development of the company’s network infrastructure.

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