The next front in U.S.-China tech battle? Underwater cables that power the global internet

U.S.-Chinese tensions surrounding technology have have sunk to sea lows.

Subsea cables hit the headlines earlier this year after four out of 15 critical submarine cables in the Red Sea were cut amid attacks by Yemen's Iran-backed Houthi rebels on Israeli U.S., and U.K. ships.

Public awareness of submarine cables has grown as a result — and these networks of cables are becoming a new source of strain in international relations, amid heating geopolitical engagements between the U.S. and China.

Buried deep underwater are hundreds of massive telecommunications cables spanning a length of nearly 1.4 million kilometers, according the telecom market research firm TeleGeometry.

Some of these cables are shorter, such as the 131-kilometer CeltixConnect cable linking Ireland to the U.K., for example. Others, however, run for far longer distances — like the 20,000-kilometer Asia America Gateway cable.

The number of subsea cables around the planet is expected to increase in the coming years, reflecting growing demand for data traffic prompted by the spread of video streaming and cloud services.

As of early 2024, TeleGeometry said its data tracked 574 active and planned submarine cables.

Subsea cables are the backbone of the global internet, carrying 99% of the world's intercontinental data traffic.

"If you have e-mailed, texted, or video chatted with someone on another continent, you've used a subsea cable — likely without giving it a second thought," Andy Champagne, chief technology officer of Akamai Labs, told CNBC via email.

"While we're linked together with a complex physical web of fiber optic cables over land, the topology becomes more challenging once we plunge into the oceans," Champagne added.

"It's really complex to install subsea