Nation-States Suspected of Cutting the Cords in Emerging Form of Warfare

Taiwan suspects a Chinese-linked ship cut undersea telecommunications cables connecting the country to the rest of the world.

This January 2025 incident follows one in November 2024 where Russia is suspected of severing telecommunications cables in the Baltic Sea, as well as a disruption to an electric cable under the Baltic on Christmas Day that led Finland to seize and inspect a tanker it links to Russia.

In all cases, the severed cables caused only minor disruptions, underscoring the importance and utility of the redundancy that is built in to much of the world’s undersea cable network. However, undersea cables are the vital backbone of the world’s telecommunications infrastructure—the BBC reports that 99 percent of the world’s digital communications rely on undersea cables. The suspected attacks highlight the vulnerability of this backbone when nations increasingly engage in hostile acts to disrupt it that still fall short of open conflict, a so-called “gray zone” between war and peace. The tactics are also described as part of “hybrid” warfare, which is the deployment of mostly nonkinetic tactics outside of armed conflict designed to hamper or subdue an adversary.

The incident off the coast of Taiwan illustrates the difficulty countries have in dealing with these potential acts of sabotage. The suspected vessel is owned by a Chinese company, but flies under the flags of Tanzania and Cameroon. Most commercial maritime vehicles have an Automatic Identification System (AIS) transponder that provides location, name, course, and other information. Part of the Taiwan investigation now involves the examination of suspicious AIS data.

“Analysts and officials say that while it is difficult to prove whether damage to these cables is intentional, such an act would fit a pattern of intimidation and psychological warfare by China directed at weakening Taiwan’s defenses,” The New York Times reports. China denied the allegations.

The cable in the Baltic Sea Christmas Day incident was not a telecommunications cable; rather it connected the power supplies of Estonia and Finland. The severed cable interrupted the transfer of 659 megawatts of power daily from Finland to Estonia.

Finland impounded a nearby freighter named Eagle S, which is registered in the Cook Islands, but was carrying Russian oil. Finland alleges that the freighter was part of a fleet of older tankers Russia is using to avoid sanctions on Russian oil exports.

“A Finnish official said there is a track on the ocean floor dozens of kilometres in length, and that the ship’s anchor is what severed the Estlink 2 power cable between Finland and Estonia,” The National Post reported. The tanker “now appears to be missing its port-side anchor.”

In November, several European countries suspect sabotage in the severing of two fiberoptic cables in the Baltic Sea, one between Finland and Germany and one between Lithuania and Sweden. Danish warships surrounded the Chinese cargo ship suspected of being involved in the incident. The Wall Street Journal reported that the ship dropped anchor and continued moving. The vessel’s AIS was down at the time. Examination of the anchor showed evidence of being dragged and severed cables.

“Several Western law-enforcement and intelligence officials said they didn’t think the Chinese government was involved in the incident,” The Journal reported, “but that they suspected Russian intelligence agencies were behind the sabotage.” Russia denied the allegations.

TeleGeography is a company dedicated to data related to the telecommunications industry.

“Submarine cables break all the time,” TeleGeography noted on its website. “On average, two to four break somewhere in the world every week. While damage is more common in some areas than others, these breaks—or ‘faults’—eventually happen to almost every cable.”

In 1929, an earthquake off the coast of Newfoundland, Canada, led to the discovery of a new phenomenon: a submarine landslide. This rush of water snapped transatlantic cables one-by-one in succession, and underscores that incidents caused by nature or accident serve to obfuscate those actors with more nefarious intentions.

Protecting the undersea network of cables and pipelines has been an increasing area of concern for NATO as gray zone or hybrid actions intensify because Europe and the United States find themselves increasingly at odds with China and Russia.

“As great power tensions escalate, undersea infrastructure serving the Euro-Atlantic community has emerged as an attractive target for hybrid interference, meaning that the security of this infrastructure should be a NATO priority,” an article in NATO Review said in its introduction examining the topic.

All but two percent of the world’s 1.2 million kilometers of undersea telecommunications cable is owned by four companies: U.S.-based SubCom, France-based Alcatel Submarine Networks (ASN), Japan-based Nippon Electric Company (NEC), and China’s HMN Technologies.

The Center for Strategic and International Studies issued recommendations primarily aimed at the United States in an August 2024 paper.

• The United States and its allies should enact policies that ensure companies from these countries can compete with Chinese companies on contracts for placing and overseeing undersea cables.
  
  
• The United States needs to increase cable repair capability.
  
  
• The United States should lead a global effort to develop and implement a cohesive international legal framework the defends and protects undersea cable networks.
  
  
• The United States should work to streamline the regulatory burdens companies building undersea networks face. Because the area has become so time-consuming and burdensome, it discourages companies from entering the space.
  
  
• The United States should work closely with allies to engage in regulatory cooperation and to aid countries with emerging economies with technical assistance on undersea cable networks.