TL;DR: A hostile ballistic missile was intercepted above the Kármán line. This has happened before, but only during testing. No treaties were violated. No space marines were deployed.
We are out of the demo zone. We've had lots of 'demo's of interceptors.
Now it just got real. When products move from 'testing' to 'customer'.
Not only can a small adversary launch a ballistic, the defenses also worked.