Could China and Russia Destroy Starlink? Only with a Boomerang

Not an expert - but the legal/diplomatic/regulatory "attacks" would be slow and uncertain, and the US would obviously push back hard. Jamming is localized by definition. Direct physical destruction obviously invites counter-destruction - which could escalate fast, possibly to nukes.

Vs. cyberattacks? I really would not want to be Starlink's head of cybersecurity.

Perhaps the US should "leak" a study on how fast a few Falcons launching ball bearings into LEO could DDOS space?