The EU Separation of Sovereignty from Territory has failed.
It must now be clear to all, that while Sovereignty, in the form of the "power to Govern" has been smashed to smithereens, the EU has, in most meaningful respects, failed and is now entering its terminal stages of collapse. "Abnegation of Sovereignty," the term for the process chosen by the EU founders, has clearly failed, as it was ever an impossibility, such as being half pregnant!
The attempts by the former nation states to retrieve their national sovereignty will be trying for their citizens! Whether territorial disputes over new borders can be avoided seems moot at present, but the quicker a start is made, the sooner the danger of new wars will pass and the faster the more difficult task of establishing new relationships can begin.