With no ties to the military himself, he didn't know who would be loyal to the constitution or not. There was someone who could help, but Pence made Flynn nuclear and Trump, not understanding he was being rope-a-doped from making any smart changes in the brass, wouldn't reach out to him.

This is what was so frustrating about it all. Trump talked the talk and walked the walk where he could but in places he could not he simply did nothing instead. Half measures result in the obvious outcome: traitors maintain control while his giant blind spot provided a breeding ground for even more sedition.