Basically, the problem is that the military has to be subservient to the political arm of the US Government (in the case of lawful orders), otherwise that opens up a very dangerous door.
However, what if that government goes directly against the Constitution of the United States?
For instance, the oath of enlistment in the US Armed Forces:
"I,(your name) do solemnly swear that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; and that I will obey the orders of the President of the United States and the orders of the officers appointed over me, according to regulations and the Uniform Code of Military Justice. So help me God."
Note that there are a few possibilities of conflict within the oath. What if the executive or legistative branch oversteps it's bounds Constitutionally? Who interprets that? From the oath, it could be down to the individual.
Baltika, I like this idea...but I'd have to agree with EricJ, I'd say it would be chaos at the individual bases for a while...
FC
PS And the 100th FTS is my old unit...til they took it away from us....grrrr....