AUGUST 2024
Safeguarding Subsea Cables
Protecting Cyber Infrastructure amid
Great Power Competition
By Daniel Runde, Erin Murphy, and Thomas Bryja
S
ubsea ber-optic cables, a critical information and telecommunications technoloy (ICT)
infrastructure carrying more than 95 percent of international data, are becoming a highly
consequential theater of great power competition between the United States, China,
and other state actors such as Russia. The roughly 600 cables planned or currently operational
worldwide, spanning approximately 1.2 million kilometers, are the world’s information
superhighways and provide the high-bandwidth connections necessary to support the rise of cloud
computing and integrated 5G networks, transmitting everything from streaming videos and nancial
transactions to diplomatic communications and essential intelligence. The demand for data center
computing and storage resources is also expected to increase in the wake of the articial intelligence
revolution. Training large language models takes enormous, distributed storage to compute, and if
those networks are globally oriented, they will require additional subsea capacity to connect them.
These geopolitical and technological stakes necessitate a consideration of the vulnerabilities of subsea
systems and the steps the United States can take to fortify the digital rails of the future and safeguard
this critical infrastructure.
Undersea Cables: Why Do They Matter?
Subsea cables are critical for nearly all aspects of commerce and business connectivity. For example,
one major international bank moves an average of $3.9 trillion through these cable systems every
workday. Cables are the backbone of global telecommunications and the internet, given that user data
(e.g., e-mail, cloud drives, and application data) are often stored in data centers around the world. This
infrastructure eectively facilitates daily personal use of the internet and broader societal functions.
In addition, sensitive government communications also rely extensively on subsea infrastructure.
While these communications are encrypted, they still pass through commercial internet lines as data
traverses subsea infrastructure. Subsea cables carry a much larger bandwidth and are more ecient,
