Should we be preparing for an intercontinental nuclear war?

The USA has throw-weight on several continents plus ballistic missile capacity for several continents but what about a bright boy alert or when confidence is high for the USA?  Should the Jews be prepared both on Israel and abroad? Who can say?  The winners are those destroyed in the blasts because an existence in nuclear fallout is hell. Who will be the first country to explode nuclear devices in war again? https://www.youtube.com/watch?v=wbl_ElsgtJY