Options to repair underseas fiber-optic cables in the event of war or sabotage are limited.

Undersea cables damaged to cut communications ? More predictive media around this from US Naval Institute:

Repairing Submarine Cables Is a Wartime Necessity

Options to repair underseas fiber-optic cables in the event of war or sabotage are limited.

“What should the U.S. do when the transoceanic submarine fiber optic cables that supply, at the speed of light, more than 99 percent of the international voice, data, video, and internet communications between the United States and the rest of the world are damaged or cut during wartime?

Declare an emergency? Then what?”

Navy Cable Ships

DoT also may believe the Department of Defense (specifically, the Navy) should handle cable repairs. However, the Navy does not have repair responsibility for commercial submarine telecommunication cables.

Given that commercial cable responsibility requires commercial cable ships and Merchant Marine crews, the MarAd—as selected by the National Security Council when the CSF was created, with deep experience operating the 60-ship Maritime Security Program with more than 60 commercial container, roll-on/roll-off ships, and other U.S.-flagged and -crewed merchant ships that can activate in wartime—is the logical agency to operate the CSF in peacetime.

To read more click the link below

https://www.usni.org/magazines/proceedings/2022/october/repairing-submarine-cables-wartime-necessity