Clearly, as the President explained at the U.N. General Assembly last week, ISIS must be destroyed. But, ISIS is a symptom of the problem - authoritarian governance in the region. Destroying ISIS through a multilateral coalition provides a signal that the Arab and Muslim societies in the region reject the ideals of ISIS. In destroying ISIS, Washington needs Riyadh and the UAE, but Riyadh and the UAE do not need Washington. But, we fear that after ISIS, then what? .... another variation of ISIS appears. This can devolve easily into a long war of attrition in Syria.
Defeating ISIS alone does not resolve the problems of regional authoritarian leadership that only serves to mobilize the disaffected populace to seek recourse through other means, like ISIS, to address their grievances.
So, an all-out offensive attack on ISIS is a short-term reaction to a symptom that will only re-emerge in other forms. The problem must be resolved by the regional leaders, where the U.S. can only provide a supporting role; careful not to allow others to perceive that the U.S. is attempting to dictate terms to other leaders.