Roughly 200 undersea cables are cut or disrupted every year, most often by fishing gear and anchors.[1] The geopolitical question is what happens when the second most common cause — a ship's anchor — is used on purpose, and who is equipped to tell the difference.
On 17–18 November 2024, two submarine cables were disrupted almost simultaneously about 60–65 miles apart: the BCS East-West Interlink (Lithuania–Sweden) and C-Lion1 (Finland–Germany).[1] Germany's defence minister called the damage sabotage; Finland and Germany's foreign ministers issued a joint statement of "deep concern" over suspected hybrid warfare.[1] The BCS East-West Interlink carried roughly a third of Lithuania's internet capacity at the time.[1]
The suspect was a ship: the Chinese bulk carrier Yi Peng 3 crossed both cable positions on the night of the cuts, sailed 7.5 hours with its AIS transponder switched off, and later showed an anchor with fresh damage.[1] Investigators told the Wall Street Journal they believed the crew dragged the anchor across the seabed for over 100 miles, possibly at the inducement of Russian intelligence.[1] Denmark's navy shadowed and effectively detained the vessel off Kattegat for weeks; boarding required China's consent, and the detention became the first enforcement action under the 1884 cable convention since 1959.[1] Both cables were restored by 28 November 2024.[1]
A month later the pattern repeated on a power cable. On 25 December 2024, the Estlink 2 Estonia–Finland electricity interconnector failed (capacity 1,016 → 358 MW), and the same evening four telecom cables were reported disrupted, two of them Elisa's, completely severed.[2] The suspect: Eagle S, a Cook Islands-flagged tanker believed to be part of Russia's shadow fleet, which crossed the cable line at the moment of the outage — and made a U-turn back toward Russia half an hour later.[2] Investigators mapped an anchor drag track on the seabed "several tens of kilometers long"; the anchor itself was recovered on 7 January 2025.[2] Repairs to the power cable took until June 2025 and cost tens of millions of euros.[2] Washington Post later reported anonymous US intelligence assessments that the November–December 2024 cable events were accidents, a claim sharply disputed by Baltic officials.[2]
The Baltic failures were also a live experiment in network resilience. RIPE Atlas measurements showed that after the cuts, 20–30% of measured paths between the affected country pairs saw higher latency, but no significant packet loss — traffic detoured onto other links and kept flowing.[3] The RIPE analysis concluded the Baltic internet "managed to route around the damage," with enough backup capacity to absorb two simultaneous cuts without an outage.[3]
On 25 February 2025, Taiwan's coast guard intercepted the Togolese-flagged cargo ship Hongtai in the waters between the island's west coast and the Penghu Islands, after Chunghwa Telecom reported a cable severed 6 nautical miles northwest of Jiangjun Fishing Harbor — an area where Hongtai had been anchored since Saturday evening.[4] Authorities had signaled the vessel seven times without response.[4] The coast guard said the case would be handled "in accordance with national security-level principles," and that "the possibility of this being part of a gray-zone incursion by China cannot be ruled out."[4] Communications on Penghu were not disrupted because a backup cable took over.[4] Taipei's stated fear is broader: China might damage Taiwan's cables "as part of attempts to blockade or seize the island."[4]
In April 2025, the captain of the Hongtai, surnamed Wang, was charged under Taiwan's Telecommunications Management Act for "destroying submarine cable-related facilities" — against a backdrop of 14 international and 10 domestic submarine cables.[5]
A July 2025 assessment from Recorded Future's Insikt Group argues the repair layer is the real strategic bottleneck: more than 90% of Taiwan's internet traffic flows through submarine cables, and in a crisis Chinese authorities, especially the coast guard, could prevent repair vessels from accessing damaged links.[6] The report counts five submarine-cable damage incidents around Taiwan between 2024 and 2025, and four in the Baltic; of the nine, five were caused by ships dragging anchors, four linked to China or Russia directly or through opaque ownership.[6]
The pattern persists where installment 1 left it. In September 2025, cable cuts in the Red Sea near Jeddah slowed internet across India, Pakistan and the Middle East; Netblocks identified failures affecting cable systems near Jeddah, and Microsoft said Azure traffic was being rerouted with higher latency.[7] The cause was not immediately established.[7]
The anchor is the perfect gray-zone weapon because it is also the most common accident: the same evidence either way.
The Baltic cases show the limit of the weapon. Enough route diversity, and a cut is a latency blip, not an outage.
Taiwan shows what a strategically placed cut can still achieve: with more than 90% of traffic on cables, blocking the repair vessel may matter more than the cut itself.
Attribution is slow, legal and diplomatic — the first enforcement of the 1884 cable convention in 65 years was itself a geopolitical event.
[1] en.wikipedia.org/wiki/2024_Baltic_Sea_submarine_cable_disruptions — Wikipedia: 2024 Baltic Sea submarine cable disruptions
[2] en.wikipedia.org/wiki/2024_Estlink_2_incident — Wikipedia: 2024 Estlink 2 incident
[3] labs.ripe.net — RIPE Labs: Does the Internet Route Around Damage? (20 Nov 2024)
[4] thehindu.com — Taiwan investigating Chinese-crewed ship believed to have severed undersea cable (25 Feb 2025)
[5] newindianexpress.com — Taiwan charges Chinese ship captain with cutting undersea cable (AFP, 11 Apr 2025)
[6] telecom.economictimes.indiatimes.com — China may block Taiwan's undersea cable repairs: Recorded Future Insikt assessment (23 Jul 2025)
[7] hindustantimes.com — Red Sea cable cuts disrupt internet across Asia and the Middle East (7 Sep 2025)