What should USA do? Turn around and go home, or stay and fight, even if that means...

If it meant 100 percent that we woudn't get nuked from NK or anyone else for the next few years, should we just "turn around and go home" or is it worth it to stay and protect SK even if it means risking losing everything we love at home. Just seems that that is the choice they are giving us. So I wanted to ask you guys what you think we should do.