The modern world runs on a fragile network hidden deep beneath the ocean. Thousands of miles of undersea fiber optic cables carry nearly all global internet traffic, financial transfers, military communications, and commercial data. According to reports cited by U.S. officials, these cables support up to $10 trillion in financial transactions every single day and carry roughly 99 percent of global data traffic.

Security experts now warn that China increasingly views these cables as a strategic target that could be exploited to create economic chaos without firing a missile or launching a conventional military attack.

Andrew Badger, former Pentagon official and chief strategy officer at Coalition Systems, warned that “America depends on the fragile nervous system of subsea cables for modern life.” He added that U.S. adversaries “seek to turn the bottom of the ocean into a battlefield.”

The concern is not theoretical anymore. Taiwan, Europe, and the Baltic region have all experienced suspicious cable cutting incidents involving Chinese-linked vessels, anchor dragging operations, ships operating under false identities, and vessels that mysteriously turned off their tracking systems before cables were damaged.

Why Undersea Cables Matter So Much

Most people never think about undersea cables, but modern civilization depends on them. Banking systems, stock markets, energy trading platforms, emergency communications, military coordination, cloud computing, and internet traffic all rely on these underwater arteries.

The Oxford Internet Institute warned that growing artificial intelligence systems are increasing the demand placed on submarine cables, making them even more important to the global economy.

If enough cables were cut simultaneously, the effects could be catastrophic. Financial transactions could fail. Internet service could collapse in entire regions. Emergency systems could be crippled. Military communications could be delayed or disrupted.

Badger warned that “a coordinated strike on American undersea infrastructure could fundamentally disrupt our way of life. The internet, banking, energy markets and military communications all run through these cables.” He added that “the dollar cost is almost incalculable, and the real damage would be the chaos and political instability that would follow.”

What makes this threat especially dangerous is how asymmetric it is. A relatively small number of ships or operatives can target infrastructure spread across enormous stretches of ocean that are almost impossible to fully defend.

As one analysis noted, these cables are “ideal targets for sabotage with minimal resources, while creating just enough plausible deniability for malicious actors to dodge any consequences.”

The Techniques Used to Damage Cables

Investigators and analysts have identified several methods repeatedly used in suspicious incidents linked to Chinese vessels.

The most common involves dragging anchors directly across known cable routes. Ships often loiter near cable zones, move at unusually slow speeds, disable tracking systems, and then drag anchors along the seabed where cables are located. Because accidental anchor drags do occasionally happen worldwide, this provides built in deniability.

Kevin Frazier explained the strategy clearly: “The simplest way for a bad actor to break a cable is to make it look like one of the accidents that commonly cause such breaks.”

Another expert, Ray Powell, described the gray zone logic behind these operations: “You just have to be just deniable enough so that even though everybody knows it’s you, they can’t prove it’s you.”

China has also openly developed specialized cable cutting technology. In 2025, China’s Ministry of Natural Resources confirmed testing an advanced deep sea cable cutting device capable of slicing armored submarine cables at depths of 3,500 meters. Researchers at China’s Lishui University also reportedly designed anchor-like cable cutting devices optimized specifically for sabotage operations.

U.S. officials are additionally concerned about Chinese repair ships operating near strategic cable systems. According to reporting discussed by the Wall Street Journal, Chinese state controlled repair vessels repeatedly turned off transponders and concealed their movements while working around sensitive undersea infrastructure.

A Growing Pattern of Incidents

The International Cable Protection Committee estimates that 150 to 200 cable faults occur worldwide every year, most of them accidental.

However, analysts say the repeated clustering of suspicious incidents around Taiwan and Europe points to something more deliberate.

Taiwan alone has reported roughly 30 subsea cable incidents in recent years.

One of the most serious occurred in February 2023, when Chinese vessels severed the only two cables serving Taiwan’s Matsu Islands. Around 14,000 residents lost most internet access for nearly two months. Analysts believed the operation revealed how Taiwan would respond during a communications crisis.

In January 2025, the Tanzania flagged Xingshun 39 allegedly dragged its anchor across a major trans-Pacific cable linking Taiwan to Asia and the United States after disabling its tracking system near Keelung.

Then in February 2025, the Togo flagged Hongtai 58 severed the TP3 cable linking Taiwan and Penghu. Taiwan later sentenced the captain to three years in prison. Prosecutors described the vessel as “highly suspicious,” noting repeated identity changes and unusual operational patterns.

Europe has also experienced similar attacks. Investigators alleged that the Chinese bulk carrier Yi Peng 3 dragged its anchor more than 100 miles across the Baltic seabed, severing cables connecting Sweden, Lithuania, Finland, and Germany. Satellite tracking showed the vessel disabled its transponder during the operation.

Analysts said the weather conditions made accidental anchor dragging unlikely. One European investigator stated that it was “extremely unlikely that the captain would not have noticed that his ship dropped and dragged its anchor.”

A Battlefield Hidden Underwater

Taiwanese officials increasingly believe these incidents are part of a deliberate strategy of gray zone warfare designed to weaken Taiwan without open conflict.

Herming Chiueh, Taiwan’s deputy digital minister, warned, “Some scholars have said that World War III could begin with the cutting of undersea cables. I think that’s quite realistic.”

The danger extends far beyond Taiwan. The same vulnerabilities exist across Europe and North America. Undersea cables stretch for thousands of miles and are almost impossible to defend continuously without massive naval patrols and monitoring systems.

One analysis summarized the reality bluntly: “The undersea cable conflict may seem obscure next to warplanes and missile drills, but it’s no less dangerous.”

That may be exactly why adversaries see them as such an attractive target.