This is something I'm concerned about regarding secession. If we successfully secede and form our own country with the constitution preserved, what will that mean in regards to our military?

Will so-called 'Trump loyalists' disband from the ones supporting the establishment and socialist democrats, effectively cutting our military in half (maybe 60-70% actually)? That wouldn't be ideal, I imagine.

Will the entire military end up having to join us if enough high ranking officials call for it?

Will the opposite of that happen, and we might instantly be considered an enemy nation and thus instantly invaded by both our former own military and a potential offshore enemy?

Or will the military promise to defend us regardless of our secession?

I'm not an expert on how all this works, so I'm just looking for answers on this concern of mine.