Comment by michaelt

In terms of https://en.wikipedia.org/wiki/Weinberger_Doctrine if article 5 was invoked, one could set much clearer victory conditions - chase Russia back into Russia. Maybe arrest Putin war crimes or something.

It would still be extremely unpleasant, painful and expensive, of course; winning an exchange of blows still means taking a load of punches to the face. So the true winner would be China.