It'll take some time but eventually they will officially declare a state of war which will have congress increase financial capacity and give more room to military movement.
White House Wants Bipartisan Support for War Authorization Against Islamic State - Washington Wire - WSJ
I think they will eventually send ground troops to speed up the proces of defeating ISIS but no more than 20K forces, mostly infantry & forward air controllers working together with local forces with the main objective being the restoration of the Iraq/Syria border and enforcing a barrier cutting ISIS in half as well as Mosul/Fallujah the 2 regional HQ's of ISIS of course.
I agree. An international consortium of at least 2 Army Corps would be needed to eject ISIS from major population centers in the region. Then, afterwards, the arrival of UN Peace Keeping Forces to ensure rule of law is maintained while political stability is realized.