You could say that this split already exists, in fact if not in theory, but the difference is that, in the emerging model, the EU would be legally reconstituted. The inner ring would not be permitted to dictate to the outer. The Brussels version of Sauron’s “one ring to rule them all” doctrine would be broken at last. The authors of the idea expect that it will appeal to other EU member states who either fall out of the euro in coming years, or shy away from joining it, and also to members of the European Economic Area. But if it did not do so, they would still go ahead and negotiate these terms for Britain alone.