EJK 'works' until it strikes somebody close to you ( presumably an innocent person )
It hasn't worked even with terrorism. Westgate, Mandera, Mpeketoni ... ? What it does do is increase alienation and an appetite for terrorism.
I don't consider myself "terrorist material", but if agents of a rogue state went around finishing my loved ones, I'd be inclined to strike back in some nasty way. I wouldn't be surprised if others felt that way.