AOG - "It's amazing reading the support for barbaric mutilation which seems fine to some, yet mention clipping a misbehaving child around the head, a return of corporal punishment in schools or the bringing back of humane capital punishment, and these same people's arms go up in horror."
To an extent, I believe that such support comes from the perecived notion that some Islamic nations live in biblical societies, so biblical punishments are appropriate.
Add to that the sheer distance between their culture and ours - geographically and culturally, and it's amost as if this would be happening 'somewhere else' and is not actually real.
That would chime with your point about the strong reaction to the use of corporal punishment or the notion of capital punishment - if something like that happens 'here', then we have to give it far greater consideration.