The impasse that faces both the EU and the UK results form the deeply flawed method by which the Brexit negotiations have been conducted.
These have been designed in two sequences: first to establish the conditions for an orderly withdrawal; then those of a future relationship.
Aggravated by huge political fractures on the British side, and the steely determination to maintain unity on the EU side, this approach has been driving both sides towards a brick wall.
A divorce process can only be well managed if not just the terms for a separation but also those of any alternative future relationship are mapped out.
The two sets of terms are interdependent, as is shown by the ongoing controversies within the British political system regarding whether Brexit should be hard or soft.
The UK should have been asked first to clear as a matter of principle and policy what future relationship it sought.
The EU should have indicated what relationship it found acceptable. Agreement would have been sought on this.
Negotiations would then have been about proceeding from a status of full membership to that of the proposed new relationship.
Instead another episode is being played in a soap opera that frankly has become rather dreary.