Joseph Biden actually said...

It would -- it would trigger a response in kind. Whether or not -- you`re asking whether NATO would cross -- we`d make that decision at the ...

And I sat down, and I said, 'America is back.' And one of the -- one of my counterparts, colleagues, a head of state, said, 'For how long?' ...

We would respond if he uses it. The nature of the response would depend on the nature of the use.

I think that the President and his top advisers believe it is working as it is designed to and perhaps better.