Subsea Risks: How Underwater Infrastructure Is Becoming a Frontline of Security Threats

The damage to subsea infrastructure in European waters has revealed a serious gap in how we protect critical assets beneath the ocean. At first glance, these incidents looked like sabotage—but what’s clear now is that they point to a new kind of threat. It’s not just about pipelines or cables anymore. This is about how attacks can happen quietly, without obvious signals, and with little chance of being caught. The Nord Stream attacks weren’t just about energy—they showed that maritime security isn’t just a naval issue anymore. It’s a global challenge, one that operates outside traditional lines of control and jurisdiction. We’ve long treated the ocean as a space where rules are less strict, but now that space is being exploited in ways we didn’t expect.

What’s changing is the way threats are being launched. They’re not always tied to big ships or military forces. They can come from small vessels, disguised as fishing boats, or even from underwater drones operated by people with access to training and tools. The real danger lies in the ambiguity of what counts as a legitimate maritime activity. No one’s watching every boat, and no single country has full oversight over the deep sea. That means attacks can slip through unnoticed—especially when they happen in waters that don’t clearly belong to one nation.

How Threats Are Emerging Under the Sea

• Submarine operations: State-backed naval forces could use advanced submarines to deploy explosives in international waters. These vessels can move unseen, stay below detection, and carry out attacks without triggering alarms. That means monitoring underwater activity isn’t just helpful—it’s essential.
• Surface vessel attacks – “grey zone” tactics: Fishing boats or small vessels can be used to launch divers or ROVs into restricted zones. These attacks blend in with normal traffic, making them hard to spot. They don’t need big ships or military gear—just someone with the right skills and access.
• Jurisdictional confusion: The ocean isn’t clearly divided. Exclusive economic zones overlap, and responsibility for what happens under the sea is shared among multiple countries. That makes investigations slow and hard to close. Without strong international coordination, holding anyone accountable will be nearly impossible.

The sea is no longer just a place for shipping and fishing. It’s now a domain where digital and physical threats intersect. Just like cyberspace, the ocean is full of actors—some legal, some not—and it’s hard to track what’s happening in real time. The networks beneath the surface are fragile, and they’re connected to everything from energy to communications. When one part fails, the ripple effect can spread quickly.

We can’t keep treating the deep sea as a passive space. If we don’t act now—through better sensors, smarter surveillance, and stronger cross-border cooperation—future attacks could cripple energy supplies, trigger global instability, and expose the limits of our current security models.