Do you think the Army would have fired on Americans to enforce desegregation in 1957?
We don't know, because Gov. Faubus blinked. If it came to it, I think Texas would blink now as well.
Obama is no Eisenhower, and the military is professional now, not Cold War draftee.
The officers and men have a much better understanding of the Constitution than the judiciary, and I tend to think they would sit out any such conflict, telling His Royal High-ness that this is a political dispute.