A US research group believes that Russia and China could instigate more merchant ships to sabotage the undersea cable infrastructure of political opponents.
According to the Insikt Group, these “state-sponsored” activities are more insidious and less costly than open warfare.
Insikt identified 44 publicly reported cable damages incidents in 2024 and 2025, occurring in 32 different groups. Almost one-third (31%) of these cases could not be traced back to a specific cause. In 25% of the incidents, anchor dragging was confirmed as the primary reason, while seismic activity or other natural phenomena were responsible for 16% of the damage.
“The events of the last 18 months indicate that the risk environment for submarine cables has very likely escalated, and the threat of state-sponsored malicious activity targeting submarine cable infrastructure is likely to increase further in the face of rising geopolitical tensions,” Insikt shared.
Three factors in the submarine cable ecosystem – limited redundancy in cable networks, lack of diversity in cable routes and limited global repair capacity – are seen as key contributors to the growing threat of outages.
Certain regions more at risk
Regions with low redundancy, such as parts of West and Central Africa, isolated Pacific islands and certain secondary European routes, are especially vulnerable, especially when geopolitical tensions are coupled with infrastructure bottlenecks.
Insikt continued: “Although accidents will most likely continue to cause the majority of day-to-day disruptions, recent incidents in the Baltic Sea and around Taiwan suggest that submarine cable systems remain vulnerable to threats such as anchor dragging,” Insikt’s researchers estimate. It is a simple tactic for states to attack the critical infrastructure of adversaries while maintaining credible deniability.
Four incidents in the Baltic Sea
In 2024 and 2025, four separate incidents involving eight cable damages occurred in the Baltic Sea. Five cables were also damaged around Taiwan. At least five of these nine incidents in total were attributed to vessels dragging their anchors, including four vessels linked to Russia or China that were operating suspiciously or had opaque ownership structures. However, the resulting investigations have shown how difficult it is to attribute cable breaches to state-sponsored sabotage.
“Such campaigns, attributed to Russia in the North Atlantic-Baltic region and China in the Western Pacific, are likely to become more frequent as tensions rise,” the research group explained. “Deniable tactics are used in both shallow and deep waters to exert political pressure without overt escalation.”
“Eagle S” damaged Estlink 2
In December 2024, the Finnish authorities detained the tanker “Eagle S”, a shadow fleet transporting Russian oil. The ship had allegedly dragged its anchor across the Estlink 2 submarine cable, disrupting the power line between Finland and Estonia. The “Eagle S” has been sailing again since March, but some of the crew are still in custody.
On June 12, a Taiwanese court sentenced a Chinese ship’s captain to three years in prison. He had been found guilty of deliberately damaging Chunghwa Telecom‘s submarine cable with his cargo ship “Hong Tai 8” in February. Chunghwa spent almost 580,000 dollars to repair the cable.
Without a significant increase in the number of dedicated repair vessels, repair capacity is likely to fall short of demand, which would cause the average recovery time to exceed the current benchmark of 40 days. To overcome these challenges, Insikt proposes that governments and the private sector jointly invest in repair and maintenance capacity, improve real-time monitoring and safety measures around submarine cable infrastructure, and conduct comprehensive stress testing.
