What happens if the President never concedes power to the new administration? What if that was because he had 100% proof the election was fraudulent and an overthrow by an enemy combatant under foriegn control? What would the military do if all they are sure about is there was no concession?
Who do they follow? And why?
Asking for a friend.
They follow whoever is confirmed as the winner of the Electoral College by Congress and sworn in to office. Concession is a polite tradition; it has no constitutional significance.
That seems like a real problem if your country is being stolen, or what if the President had family members in danger or kidnapped to tie his hands from stopping the insurgents? Strange there'd be no protocol for that.
The 25th Amendment is the protocol for that. If the vice president and cabinet believe the president is incapacitated (whether medically or because under duress) they can vote to remove him (which Congress must confirm by its own vote if the president denies being incapacitated).
For (hopefully) obvious reasons, the military has no independent constitutional authority to judge the legitimacy of domestic elections. They could, of course, simply refuse to obey—as they could have decided to refuse to obey Trump if enough of the military leadership had thought he was illegitimate—but they have no formal legal power to make that determination.
So how can they take an oath to protect and preserve the Constitution while allowing an illegitimate government to dive head first into communism and destroy the Constitution? It just makes no sense that there isn't anything in place for this. I read the Military code and how it pertains to belligerent governments and occupations, but if no court will even listen, then what? BLM and Antifa have made damn sure the judges are all scared or otherwise they're complicit.