It seems some armies follow CISSP recommendation to use optical fiber to prevent hacks

https://www.forbes.com/sites/davidhambling/2024/03/08/russian-fiber-optic-drone-can-beat-any-jammer/

Russian Fiber Optic Drone Beats Any Jammer (UPDATE: Ukraine Version)

The Ukrainians recently captured a Russian drone which communicates via a fiber-optic link, making it jam-proof. This looks like a big headache and not just for Ukraine.

Forbes
@dehaller the use of fiber optics is widespread in the armed forces of the world, not just the russians.
@qrsbrwn I know, I would have guessed so. I was surprised they used it in drones, where a wired connection might be unproductive. But it prevents jamming.