Follett has identified several key concepts and further identified the ways in which they lead us away from peace and prosperity. She frequently uses "real" to not a paradigmatic shift around a concept in need of profound change--a change of mind, a change of worldview.
Real Sovereignty is one such shift of mind--from fierce independence to active and constructive interdependence. From walls to bridges. The EU is one such experiment. Brexit is one casualty.
Perhaps the uniting of the states in north america is another ongoing experiment. Indeed, Texas, California, parts of Oregon have all discussed cession from the greater union.
This leaves up with the important question, what best determines the membership of any one entity, understanding that those not included will form another entity which entails a larger union in which all are members.