There are a fuckton of reasons what is going there.
Some of the main reasons aren't economicly , or polticly , not in our way of thinking anyway. While most radical islamist do hate us , here in the west , and would like to see us all killed or converted what they do hate even more than us is , each other.
All these different islamic groups are in constant fighting with each other , shiats are killing sunnis , sunnis are killing alives and so on.
While all of them are muslim , each of thouse groups sees themself as 'true' muslims and the other ones as heretics , more so than christians or jwes.
Besides this , most of them are organized in tribes , and even between tribes there is hatred and infighting.
So how are you going to stop this? The easist way is , was and will still be installing a dicator that keeps everyone in check , but this holds only for so long until he is overthrown and than , well we are seeing in syria right now how these things are going to end.

Besides this , the end goal of all these groups is installing the caliphat. While we could actually even help IsIs in installing the caliphat , and view the whole thing from the outside and see how they are going to struggle with upkeeping the entire middle east as a single nation with all their problems. It would still lead to a massiv slaughter of all the other groups , and either they are going to get killed , all of them (we are talking about millions of potential deads) or help them fo flee from the middle east.
Than still it would only lead that the caliphate would pursue the other groups , and besides this there would be the problem in where all thouse people should be going.
Europe is out of question , we do not have the ressources , nor the space or jobs for them , and beside that the caliphat would try to kill them , not giving a fuck about European casualites.Or we could ship them to africa , which would cost billions and would in the end they still wouldn't be safer because africa is highly islamic too.
Not even speaking of africa here , that would a different shithole to fix.

So they won't stop killing each other , they won't stop killing and attacking us.
They do want to install a caliphat but that would only lead to a massacre.
You cannot convince them to change ways because Islam is not only a religion , but it is a ruling system aswell , so installing a democracy changes shit , as seen in agypt were the most radical ismalic party has been voted that openly supports terrist groups.
The only thing that helps , at least for a while is installing a dicatorship in the region that keeps the groups in check.
But doing that makes them hate us even more.
So what the fuck should we do? Kill them all and be over it?
Let them be opressed by some asshole , let them kill each other without abandom?
Let them kill us , so that we start going apeshit crazy and hate and lynch random muslims so even more are going to join them?

So what to do?