In what scenario does the military not pick sides? No matter if it’s from the get go or not.
All out civil war? Same scenario, military gets involved? The side they’re on will be told to hide, they’ll shoot anyone walking around with a gun and it will come from the sky.
The second amendment was written at a time when it made sense, with today’s military it doesn’t make any anymore and it achieves the opposite of what was intended, putting people in danger instead of keeping them safe.