The tool, which is able to cut lines at depths of up to 4,000 metres (13,123 feet) – twice the maximum operational range of existing subsea communication infrastructure – has been designed specifically for integration with China’s advanced crewed and uncrewed submersibles like the Fendouzhe, or Striver, and the Haidou series.
Yeah, the only feasible way to do satellite warfare without creating a ton of debris is to mechanically attach to an enemy satellite and drop it out of orbit.
Like imagine an autonomous attacker satellite that clamps onto the target satellite, and uses thrusters to drop itself (and the target) into the ocean. Any kind of kinetic weaponry to destroy the target satellite will just end up with a debris cloud around the earth, making future space travel impossible.
But no country wants to invest in satellites just to intentionally drop them out of orbit. Every single attack would be prohibitively expensive when compared to just firing a missile at the satellite.