Eric, I'm in the Army, so, in part, I represent that force. I would never be complicit in any operation against US citizens.

I would take my chances being locked up in Ft. Leavenworth if it came down to it. Force is definitely real, but the authority to use it exists only in our minds.

 If nobody is willing to pull the trigger in the hypothetical scenario you posited, and I know that I am far from the only one whom would refuse such orders, then there is no threat. If we raise children that believe in reason over superstition and trust in ethics over authority (and live that way ourselves when we can), eventually there will be no thugs left. While it isn't fast or glamorous change, it is something we can work towards that makes a positive difference.

Most of the killing, waterboarding, etc. are only possible because Muslims have been so dehumanized in military culture (and in US culture at large).