HONG KONG — First the Baltics, now Taiwan. This month, in the latest in a spate of such incidents, crucial undersea cables connecting U.S. allies were damaged or severed. 

Some have been cast as acts of sabotage, pinning blame on Russia and China amid heightened geopolitical tensions. 

Early this month, Taiwan’s coast guard said it had intercepted the Xing Shun 39 — a Hong Kong-owned freighter carrying the Cameroonian and Tanzanian flags — after Taiwan’s biggest telecom company, Chunghwa Telecom, alerted authorities that an international undersea cable had been damaged on Jan. 3. 

A “preliminary assessment” suggested the damage might have been caused by the freighter, which “transited the area at the time of the incident,” the coast guard said.

With an average of about 200 cable faults a year, according to the International Cable Protection Committee, damage to undersea communications infrastructure is not uncommon. The majority are caused by ship anchors or fishing activity such as trawling, where heavy equipment is dragged across the seafloor. 

But the Taiwanese government says this may have been an example of Chinese “gray-zone interference,” irregular military and nonmilitary tactics that aim to wear down an opponent without engaging in an actual shooting war.

It also comes amid an uproar in Europe, where NATO is stepping up patrols of Baltic Sea cables that provide power and enable almost all intercontinental communication, including the internet. 

In Helsinki on Tuesday, members of the defense bloc with access to the Baltic Sea agreed at a summit on regional security threats — including Russian cable sabotage — to deploy frigates, patrol aircraft and naval drones in the Baltic Sea to help protect critical infrastructure.

NATO members said they reserved the right to take action against ships suspected of posing a security threat as part of a broader action, dubbed “Baltic Sentry,” in response to a string of incidents in which power cables, telecom links and gas pipelines have been damaged in the wake of Russia’s invasion of Ukraine in February 2022.

The damage from the Jan. 3 incident did not disrupt communications in Taiwan, as the data was routed to other cables. 

However, “if enough cables were cut you can potentially cause something as severe as an internet blackout,” said Ian Li Huiyuan, an associate research fellow at the Institute of Defense and Strategic Studies at the S. Rajaratnam School of International Studies in Singapore. “Especially for Taiwan’s case, since it’s an island and there’s no overland alternatives.”

China’s Taiwan Affairs Office said last week that undersea cables were damaged by “common maritime accidents” and that Taiwan, which is self-governed but which Beijing claims as its territory, was making accusations “out of thin air” and intentionally hyping up the “so-called gray zone threat,” according to Reuters.

Taiwan’s Mainland Affairs Council, which makes China policy, responded that the investigation would proceed based on the evidence.

It said Chinese “flag-of-convenience” ships “have a bad reputation in the international community,” pointing to similar cases in Baltic states in which Chinese vessels were suspected.

The race to protect cables

It can be difficult to determine whether a cable was damaged by accident or deliberately, but heightened geopolitical tensions have raised suspicions of sabotage.

Estonia said last month that it would deploy naval assets to protect cables connecting it with Finland after its Estlink 2 cable was damaged on Christmas Day. Finland is investigating a Russian oil tanker that was seized after the incident and may have been dragging its anchor along the seabed. 

“Three cases in one year cannot be a coincidence,” Finnish President Alexander Stubb said last month.  

NATO is also deploying at least two ships to the Baltic Sea area for surveillance. 

While the alliance’s heightened alert mostly involves Russia’s “shadow fleet” of smuggling ships, Chinese-owned vessels have come under suspicion as well, including in November when one freighter was detained for weeks in Danish waters after two fiber-optic cables were damaged. 

The ship, Yi Peng 3, was alleged to have damaged cables that ran between Sweden and Lithuania and Finland and Germany after leaving the Russian port of Ust-Luga, on the Gulf of Finland. The ship continued its journey after investigators from Sweden and other countries were allowed to board.

Swedish authorities said they were satisfied with the inspection and did not say whether any evidence had been found. China has said it will continue to cooperate with regional authorities in the investigation.

Though European authorities have detained ships when sabotage is suspected, in the absence of concrete proof they have stopped short of directly blaming Moscow or Beijing.

Still, the anxiety in Taiwan is heightened.

“Patrol of undersea cables is really time-consuming. It adds an extra burden and becomes more resource-consuming for the coast guard,” said Yisuo Tzeng, a Taipei-based researcher at Taiwan’s defense ministry-funded Institute for National Defense and Security Research. 

The Taiwanese coast guard said that although the intentions of the Xing Shun 39 on Jan. 3 were “impossible to confirm,” it could not rule out the possibility of the vessel “engaging in gray-zone interference.”

The coast guard said it was unable to board the vessel due to bad weather, but had asked South Korean authorities in Busan, its destination port, to collect evidence.

Data from Marine Traffic showed the freighter making erratic movements that day a few miles off Taiwan’s northern city of Keelung, where a submarine cable connects the island to both the U.S. and China.

Because the cable is also connected to China, some analysts say it may be premature to blame Beijing for the disruption.

“If there is an outage of a particular cable for half a day, for one hour, we’re talking billions of dollars of investment loss,” said Gerard Parr, who has worked on submarine cable projects and is a professor of telecommunications engineering at the University of East Anglia in Britain.  

“There’s nothing to be gained by this because there’s economic value in maintaining the cable,” he added.

While Chunghwa Telecom has not said which cable was damaged, the Taiwanese giant co-owns the Trans-Pacific Express, a nearly 11,000-mile undersea system that connects Taiwan with China, Japan, South Korea and the U.S. 

Companies from all of those places share ownership of the cables.

“We’re looking at a shared infrastructure, shared risk situation, because Taiwan and China are part of the same networks. And this fact should not be overlooked,” said Cynthia Mehboob, who studies undersea cables in the Indo-Pacific at the Australian National University. 

All seven crew members aboard the freighter were Chinese nationals, the Taiwan coast guard said. It said the ship was owned by a Hong Kong company called Jie Yang Trading, which according to public records was incorporated in 2020.

Its Chinese-national director, Guo Wenjie, denied that his ship was responsible for the damage, saying “there’s no evidence at all.”

“I spoke to the ship captain and for us it was a normal trip,” he told Reuters.

NBC News was unable to reach Guo.

Taiwan’s suspicion toward Beijing stems in part from a 2023 incident in which the 14,000 people who live on the Taiwan-controlled Matsu islands, close to the Chinese mainland, were disconnected from the internet after two undersea cables connecting the islands were cut.

At the time, authorities said a Chinese fishing vessel and freighter had damaged the cables, but said there was no evidence that it was deliberate.

The same year, another Chinese ship called NewNew Polar Bear damaged a gas pipeline between Estonia and Finland. It took months for Beijing to admit that its ship was responsible, saying it was an accident. 

“What this has done in recent years is expose the vulnerability of these cables that have been out of sight, out of mind,” Parr said.