In my opinion small regional communities can only exist in isolation. I don't see how such communities could defend against an aggression by a strong state-backed military. Putin is having a great time picking off countries one by one. Maybe if someone comes up with an anarchist religion, something that strongly motivates people to seek out and destroy governments before they grow.

I think it's like snipers in FPS games - the only thing that can REALLY stand up to a sniper is another sniper.