This question can't be answered intelligently without asking two preceding questions. One - what are the consequences if we do and, Two - what are the consequences if we don't.
I'll throw in yet a third question: Do we want to fight insurgents over there or over here?
This latest bunch is even more extreme than Al Qaeda and is hell-bent on creating their caliphate, from which they will work towards conquering the world. The one saving grace with ISIS (the extremists) is that they are Sunni and Iran is primarily Shia, thus it wouldn't seem likely that Iran would sell them a nuke.
In one sense, I'd like to see drones overhead looking for convoys of pickups with black flags and then bring in the heavy aircraft. So the Iraqis have to rebuild a few roads, I don't see that as a problem.
On the other hand, one story I read told of Iraqi men of all ages, young to old, signing up to fight the insurgents. The only problem is that they wouldn't have time for training, so the aircraft would thin out the bad guys and let the Iraqis mop up afterward.