Yah violence is pretty much the only way, they won't listen to a word we say and would just take it as a sign of weakness and just make them want to attack more
at this point it doesn't even matter how bad the Islam religion may or may not be because a lot of people who follow it are good people so nothing is going to be changed about it and there are other factors that lead these terrorists to act like this not just 100% what they learn from Islamic religion because if that was the case then all Muslims would be acting like terrorists
all they want is power and control so they shouldn't be treated like a religious group because it's much more than that therefore there is no need to dislike every muslim who follows the religion
It's sad what happened but what's even worse is being a Muslim who is now being targeted by both ISIS and other world leaders because a lot of Muslims fall victim to terrorism from ISIS as well and when we fight back using violence they are caught in the cross hairs and receive fire from both sides
there's just no sense in trying to use Islam as an argument for or against ISIS's behavior, we need to get more serious and stop debating over the religion and just get rid of these guys