MAD at the civilian level...

If communities are safer if everyone has a concealed weapon because no criminal would dare rob a store where everyone else is armed, then why not take it to the next level and introduce Mutually Assured Destruction to that principalas well? I mean, it works on a global scale. only reason we dont fuck with north korea even though they HAVE the ability to produce nukes, yet we concentrate on non-nuclear countries like iraq and iran, is because N.K. has that nice protective bubble a nuke provides a country.

Of course, this never works -- see Wild West -- somebody is going to have a quicker trigger finger.

Nuclear warfare and Gun Duels are two different types of warfare. Nukes take hours to reach targets, so shooting 15 minutes after the other guys shoots makes no difference, where shooting 15 minutes after your shot with a revolver makes one helluva difference.