They are what amounts to a guerrila army with zero air defense. At some point you have to think they are still around because someone wants them around. The refugees are out, scattered all over the world. A reasonable person would conclude that if the US, Russia, France and GB wanted them out they could reduce their home land/base to rubble in a few days.
I realize they're always going to be small cells around the world, but if you destroy any organization at the core, it has catastrophic impact.
I guess it doesn't take genius logic to assume if the world powers wanted to silence them, they would be silenced. Something's not right about it.