Years ago it was the PLO. Then the Muslim Brotherhood. Then the Taliban. Then AQ. Now ISIS. I may have the order wrong, and I might have left out a few, but the point it if/when we kill off ISIS another group will pop up and take their place.
Time to get out, all the way out. Let the Arabs and because the Europeans depend on ME oil so much they can get their hands dirty too.
But as was pointed out. Us being at war every single year is great for business.