LONDON • The saga of Britain's departure from the European Union now increasingly resembles a badly scripted TV soap opera: endless episodes, the plot keeps repeating itself, the studio props never change, the actors are not getting any younger and nobody knows how to terminate the story on a mildly happy note.

Yet, throughout these tedious proceedings which have now lasted almost four years, it was Britain which played the role of the petulant child, and the EU which came across as the adult actor, always measured in its approach, always thoughtful in its actions.