Fourteen-hundred years and these people haven’t gotten anywhere other than they have modern weapons and cell phones. We should just leave them to consume themselves in their own hatred.
This would be so easy to fix. Just stop giving them cell phones and weapons. But noooooo... We want to play nicey-nice with people whose goal is our total destruction. Also certain people want to make money from those sales.
It would not be hard to disable their communications infrastructure. I don’t believe they have the materials, the personnel, and the training to deal with that. Chaos would ensue. (Of course they’ve already got plenty of chaos.)