So when in the entire history of the United States would a nationwide alert have been appropriate?

I can see a regional alert, but nationwide? Gimme a break. Even 9/11 was a regional disaster - in the sense that only a regional alert would have been needed. This sounds like a big waste of money. I'm glad I don't watch TV.

The closest we ever came to needing this would have been when the Soviets parked 10,000 warheads off our coasts but that threat went away 20 years ago. Am I missing something?