Since it's the Iranians, the North Koreans, and the entire Islamic world they just double-crossed, I would say they fear all of the above, not to mention al-Qaeda.
This is bigger than it may seem, Qaddafi is simply the first of many who will realign to position themselves with the "strong horse" they now perceive the US to be. This is precisely what Victor Davis Hanson has predicted would happen, first humiliation, which could not have been accomplished without the very public whipping of Saddam, then fear, then capitualation. We are witnessing the process which will ultimately defeat terror.
My instincts tell me not to trust the Libyans. Perhaps the Feds showed them US invasion plans for Libya, and made them an offer that they could not refuse.
I really do have a problem buying all of this.
We live in interesting times!