I was glad to see your contributions to this thread, Aloha. I was surprised (perhaps I shouldn't have been) to see the vitriolic reaction from some here, especially since much of the attacks on Milley were either irrelevant to the topic at hand or based on assumptions not actually known to us (such as that Milley contributed this info to the book himself). Even after five pages of debate, I have a hard time reading this vitriol as anything other than reflexive opposition to anyone who is known to be less than a fan of the former President.
I think your take is almost certainly the correct one. Milley was simply considering a situation which he had to consider, because of the context of the times. It's great that the situation he considered never happened, but the fact that he considered it shows he was
doing his job, not ignoring it. I think you summed it up nicely above:
He was apparently worried about a situation of the President invoking the insurrection act and declaring martial law theoretically allowing the President to use the military to stay in power. It’s a scenario that deserved considering.
And I think the worst part of all that is the fact that it
did deserve considering, and that's not the case because of anything wrong with Milley, but rather because of something wrong with President Trump.