I don't think that they will be defeated till there are boots on the ground. I don't think that will happen till after the election. It is a proven fact that you can not defeat someone like Isis with out troops on the ground. Then if other country's help instead of always thinking that the U.S. should do it all. We are tired of war. This country has been at war for 10 years.
Did boots on the ground stop Al Qaeda? Did they stop the Taliban? Did they stop Iraq insurgency? Going back further, did they stop the Viet Cong? Uniformed troops only work when they are used the fight other uniformed troops.