A single ship's anchor dragged 90 km across the Gulf of Finland seabed severed the Estlink 2 power link and four telecommunications cables on Christmas Day 2024 — and the accused vessel, the Cook Islands-flagged tanker Eagle S, still has no final verdict. That unresolved case anchors Elisabeth Braw's new book, The Undersea War: The International Battle for Supremacy at the Bottom of the World, published by John Murray this month.

The method, Braw argues, required no sophistication at all. The potential for using merchant ships to damage undersea infrastructure is, she told Maritime CEO, "blindingly obvious". For shipowners, insurers and the forwarders who depend on cable-carried data flows, that observation cuts both ways: the threat is easy to understand, yet almost impossible to police.

Why does the Eagle S case matter legally?

The Finnish legal saga illustrates the problem precisely. The Eagle S crew deny wrongdoing and contend the damage was accidental. A Finnish district court initially ruled it had no jurisdiction over an incident that occurred outside territorial waters. An appeals court overturned that decision in August this year and sent the case back for examination.

That reversal matters beyond Finland. It signals a willingness — at least at appellate level — to stretch coastal-state authority into exclusive economic zones where infrastructure sits largely unprotected. The obvious caveat: a remand for examination is not a conviction, and the legal boundaries remain unsettled.

How does this fit the wider pattern?

The Eagle S affair did not occur in isolation. It followed the Yi Peng 3 cable investigation and has been succeeded by further suspected anchor-dragging incidents in the Baltic. Off Taiwan, cargo ships with murky identities have faced investigation over damaged communications cables, with one Chinese captain charged last year.

The 2022 Nord Stream pipeline explosions also remain in the headlines. German investigators have identified seven Ukrainian suspects, with one charged and facing trial in Hamburg — a fresh spotlight on one of Europe's most consequential acts of infrastructure sabotage.

For carriers and their P&I clubs, the pattern raises a concrete commercial question: how do you underwrite a fleet operating in waters where a dragging anchor can trigger international criminal proceedings? For shippers and forwarders, the exposure is indirect but real — the same cables carry the transactional data on which container bookings, customs filings and payment flows depend.

Are governments any better prepared?

Braw, a senior fellow at the Atlantic Council who leads research into threats to the global maritime order, believes European governments are considerably better prepared than they were in 2021. The Baltic states in particular, she notes, have improved their coordination. Taiwan faces a parallel challenge as pressure on its surrounding waters grows.

Readiness, however, is not the same as authority. What can a coastal state lawfully do when a foreign-flagged ship threatens infrastructure beyond its territorial sea? How far can intervention go before it stretches international maritime law to breaking point? There is, Braw cautions, "a limit in what you can do". The deterioration of the global maritime order, she argues, only sharpens that constraint.

The book ranges from the Baltic to the Pacific, drawing on interviews with naval officers, undersea engineers and cable operators. Its core thesis is sobering for logistics professionals: modern economies depend on infrastructure that is difficult to monitor and harder still to defend — roughly 99% of intercontinental data traffic travels through cables that most supply chain risk models never mention, a dependency Braw documents case by case rather than asserting in the abstract.

What comes next?

Braw started writing in October 2024, having followed the subject far longer, and events have barely allowed the manuscript to stand still. Another maritime book is in prospect, though no publishing agreement has been signed.

After years examining the confrontation beneath the waves, she sees no shortage of material. "There is so much happening in maritime, so much drama," she says.

With anchor-dragging investigations multiplying from the Baltic to the Taiwan Strait and appellate courts now testing the limits of coastal-state jurisdiction, the legal framework governing who may act — and how far — looks set to remain the sector's most contested question into 2026.