SpaceX and Starlink got most of the funding strait from the DoD. The Spaceforce Branch of the US Military has 100% full controll over the whole constelation if they need to.
Using Musk as a Front to launch a shit ton of Satelites is just a good front so people arent enraged the US Military but so many new sats up.
They Squat on the best orbits so the chinese cant take those. They can be uses for Signal inteligence. They even can be uses as distributed SAR lens for observations. Possible even for the interception of balistic Missiles once there are enouth of them up there.
The military implication are enormus. It is the High ground you wana have. Making the world thing thay this wasnt an American Defense projekt was the best psyop ever pulled.