How soon after identification are they shooting them down?

Like if they are watching the launch and then waiting 2 days, the adversary isn't learning the whole story.

Those are advertised as a "don't even bother" signal. There's a reason NORAD is a relatively vocal agency.

The full capabilities of satellite and sonar are hidden, but they're easily past the "good enough" line for any relevant military activities.

Best to assume the US also knows this and is revealing (or not revealing) its capabilities accordingly.