These are the large underwater highways on which almost all our Internet connections depend. Giant fiber optic cables, coated with steel and plastics, buried in shipping routes congested with merchant ship traffic, mostly running along the seabed. Ships know where they are and must avoid anchoring on top of the cables to prevent damage. However, news of submarine cable cuts frequently emerges in waters as distant as the Baltic Sea and the South China Sea.
In Europe, Russia has been pointed out as responsible for a hybrid underwater warfare. Last December, a 170-kilometer underwater cable connecting Finland and Estonia was damaged. Both countries blamed the Putin regime. In November, a 217-kilometer cable between the Swedish island of Gotland and Lithuania was disconnected. Just 24 hours later, another communication cable of 1,200 kilometers between Finland and the German port of Rostock was broken.
Following these two recent incidents, the Danish navy detained a Chinese bulk carrier for its alleged involvement in submarine sabotage in the Baltic Sea. However, several researchers blamed Russia for using the Chinese-built ship, a country also not free from suspicions of hybrid warfare, but in its case closer to its coast, in the waters surrounding Taiwan.
On Tuesday, the Taiwanese coast guard detained a cargo ship registered under the Togolese flag but with a Chinese crew, suspected of cutting an underwater cable near the Penghu Islands, in the disputed Taiwan Strait. Taiwanese authorities stated, "The possibility of a deliberate gray zone act cannot be ruled out," referring to interference by Beijing.
Just a month ago, two submarine cables connecting Taiwan to the outlying island of Matsu were cut. A ship registered in Cameroon, also with a Chinese crew, was detained on suspicion of dragging its anchor over one of these cables, which was funded by the United States, the main international supporter of this island that China considers a separatist province.
The Taiwanese coast guard reports that in both the recent incident this week and the January incidents, the detained ships had turned off their Automatic Identification System (AIS), which transmits the vessel's name, class, and location.
Taipei frequently expresses concern about the fragility of its internet connections in the face of a possible attack by the Chinese military, which could easily isolate a self-governing island that sends and receives around 95% of its data traffic through fiber optic cables extending across 14 cables. These cables land at four coastal locations in Taiwan.
In the past three years, the Chinese People's Liberation Army (PLA) has conducted up to four major invasion drills around Taiwan. In all of them, they deployed their ships and combat aircraft around the island to hinder any rapid military assistance from allied forces in Japan, the Philippines, or the US. According to veteran former PLA general Wang Hongguang, the strategy after the blockade would be to bombard Taiwanese military targets for 24 hours, critical infrastructure such as power plants and fuel depots, and cut the submarine cables.
In addition to being key players in a future clash between China and Taiwan, these cables are also crucial infrastructure in Beijing's so-called Maritime Silk Road. China tasked its telecommunications giants (Huawei, China Telecom, China Mobile, and China Unicom) years ago with investing in the construction and maintenance of submarine cables worldwide (there are over 500 assets carrying 99% of intercontinental data and reaching around 1,400 coastal landing stations).
This raised concerns in the West about the Chinese regime's plans to dominate a future cyberwar or enhance its espionage using these connections. China Unicom was the main investor in the 5,800-kilometer cable connecting Brazil to Cameroon, which became operational in 2020. It has also participated in other submarine infrastructure projects to connect Africa to Europe.
While China has been striving to penetrate internet pipelines, in the US, aware that these are critical strategic assets in conflicts, efforts have been made to exclude Chinese companies from ambitious submarine cable projects in vast expanses of the Pacific, with the help of allies like Australia and New Zealand. It is the new Cold War under the sea.