Keep in mind that the rebels are affiliated with al Queda and the Muslim Brotherhood, and persecute the Syrian Christian population, who Assad has been protecting from the Islamists.
We need to stay out. There are no good guys there 9except the Christians caught in the middle).
As far as the Middle East is concerned, the whole place could just disappear and I would be fine with that.
Besides, you could only Nuke them if the wind is blowing Northwest so Israel won't be harmed.