Hulk Smash!!!
Ahem.. Sorry if that's juvenile. Seriously though, ISIS must be fought. Simple as that. I hate war, but sometimes the world calls for "just wars".
I agree with you completely.
The thing that makes this situation even more crappy than it has to be is the fact that they use the innocents of countries as shields and are not bound to one country, it would be a very bloody war and likely lots of countries would have to be invaded in order to take out their command and to leave them in a state of disrepair, this would start multiple wars, because some of the country's leaders are sheltering ISIS. In order for success there would have to be an alliance between multiple countries and that alliance itself must share the blame for attacking all countries that ISIS occupies itself in and the alliance would have to work as one so that none of the countries in that said alliance would be blindsided by attacks from many different countries.
I do believe that ISIS must fall otherwise they can and likely will cause irreparable damage to many parts of the world with the nuclear weapons they are building. The world already sucks enough, no need to add complete chaos and fear to everyone's daily routines.