As I've said, the only way to fix this problem is with live bullets.
They might keept at it for awhile but eventually there will be no one left to shoot dead 
What about those who send the foot soldiers?
It's like the riots in the US. The rioters are mentally ill hardcore junkies; they are not the ones pulling the strings.
You fix obviously won't happen. Who would pull the trigger?
The pyramid:
The battering ram at the bottom - the rioters
Then you have the left including academics who said they are just like us. The ones who ignored the IQ factor.
Then you have the "every single time" at the top. Who was gloating over Ceuta; who said it was just desserts? It's their revenge.
It's always like this.