As numerous other posters have said, I do not believe that the Military will take orders from Obama. I do not believe that the average soldier will go against his kin or neighbors. I believe the post about Christmas time that mentioned that some high ranking brass had said that if Obama attempts to install martial law, that their first duty will be to remove him from the office.
Military will not go against us. Bush signed a mutual aid agreement with Canada, that said that in case something like this happened, that Canada will come in as the peace keeper. Good idea, they have some real cool guns and equipment that would look good in our collections.
I do think that you are right about the military not accepting illegal orders from zero.