Almost everything you do online crosses the ocean floor. More than 750,000 miles of fibre-optic cable carry the overwhelming majority of intercontinental data — including an estimated ten trillion dollars in financial transactions each day — through a few hundred fragile lines resting on the seabed. Since late 2023, someone has been cutting them.
In the Baltic alone there have been at least eleven incidents. On the last day of 2025, Finnish forces boarded a cargo ship suspected of dragging its anchor across a cable linking Finland and Estonia. Around Taiwan, the lines to outlying islands have been severed repeatedly. Investigators keep finding the same signature: a commercial vessel — often part of Russia's "shadow fleet," or Chinese-flagged — dragging its anchor for tens or hundreds of kilometres across the bottom.
This is what analysts call the "gray zone": damage calibrated to fall short of open war and to be almost impossible to prove. A ship can always say its anchor slipped. Attribution is murky, and the law is worse. The vessels do their work in international waters or exclusive economic zones, where no coastal state has clear authority to stop or prosecute them; in October 2025 a case against one suspect tanker was dismissed for want of jurisdiction, laying the gap bare.
Governments have begun to move. In February 2026 the European Union put €347 million into a cable-security package and a rapid-repair pilot, and NATO has stepped up Baltic patrols. But patrolling three-quarters of a million miles of undefended line is impossible, and the deeper weakness is repair, not protection: the specialised ships that mend breaks are few and ageing, and a single cut can take weeks to fix. The infrastructure the modern economy treats as invisible turns out to be both the most critical and the least defended terrain on Earth — a front line no one can see, on a seabed no one watches.
Sources
The scale and the cuts: Straight Arrow News on the volume of traffic and the length of cable at risk; the US Senate's undersea-infrastructure bill documenting eleven-plus incidents around Taiwan; the Atlas Institute on the Baltic incidents, the New Year's Eve boarding and the dismissed prosecution. The gray-zone problem: the Bulletin of the Atomic Scientists on seabed sabotage as calibrated, deniable pressure. The response: the Atlas Institute and the Atlantic Council on the EU package and NATO's Baltic patrols.
Further Reading
The case for caution on blame: Recorded Future's analysis that accidents still cause most cable faults and that attributing cuts to sabotage is genuinely hard — a check on the rush to name culprits. The overlooked weak point: CEPA on why the cable landing stations onshore may be more vulnerable than the cables themselves.