From the Cambridge dictionaries online:
stand your ground
to refuse to be pushed backwards, or to continue in your beliefs in an argument
What exactly does pushed backwards mean? LIke an enemy is approaching and you are stepping back? Metaphorically -- retreating?
Literally or metaphorically.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.