Turkey has an armed force which contains close to one million soldiers. They are trained, they are led by excellent officers and the problem of corruption is of scant concern. Turkey has the capability of wiping out ISIS in Syria with its armed forces. Of course, it can readily close the border between Turkey and Syria to prevent terrorists from walking into Syria and aiding ISIS.
Of course, this would require President Erdogan to cease playing a poor imitation of the Strong Man of the Year and become a serious partner in the fight to end ISIS as a key force for evil. Turkey can handle this entire operation by itself without ANY aid from outside forces.
Problem: Erdogan insists that President Assad depart, quickly. How about a meeting between Obama, Putin and Erdogan which outlines a plan that allows Assad three more months of power and then he departs for Saudi Arabia?