The heated US-China cable competition under the seas | South China Morning Post

Vital for data transmission and communications between continents, lines are vulnerable to sabotage and a stage for global power rivalry

It was just the latest expression of US concern over China’s potential espionage in handling network traffic, an accusation Beijing has repeatedly rejected.

Usually running along the bed of the world’s seas, undersea cables are the backbone of the global internet for daily communications.

About 95 per cent of the US population and nearly 75 per cent of China’s use data that is transferred through undersea cables, and the number is growing.

As global powers jockey for technological and economic supremacy, undersea cables are increasingly at the centre of the competition.

Here are five things to know about the undersea information network, and what it means to the US-China relationship.