David Davis surely produced one of the most memorable one-liners of the Brexit saga when he told an audience in Berlin on 16 November:
"Putting politics above prosperity was never a smart move".
Commentators pounced on the delicious irony that this pearl of wisdom came from the representative of a country engaged on doing serious damage to its prosperity in pursuit of a tangled web of political objectives.
For me, it also laid bare a fundamental misunderstanding at the heart of Britain's negotiating strategy. I think Davis was really making a plea that the EU's commercial interests in trade with the UK should drive their negotiating position.
In other words, the old Brexiteer reasoning that, because the continentals sell us a lot of cars and prosecco, indeed have a trade surplus with us, they will fall over themselves to fix us a Free Trade Agreement giving the benefits of being in the single market without the disciplines.
Sure enough, Davis briefed his bemused listeners on the scale of German automotive and other exports to the UK, and the fact that the single market meant that a car only had to undergo one set of approvals, in one country, to meet the required standards across the EU. Then he reminded them of all that Britain had been doing to expand cross-border trade in services, and how it was in our mutual interests that all these good things should continue after Brexit.
I think I detected, not far below the surface of this curious speech, a cry of frustration, of bafflement, that the Germans wouldn't see their evident self-interest. Why were they being so difficult in the first phase negotiations, especially over the money? Didn't the script say that Mrs Merkel should be riding to our rescue at this point?
That's the misunderstanding. For the Germans, the French and the other founder members, the central purpose of the European project has never been primarily about commerce. From the outset it was about peace and reconciliation, about values and justice. About politics, if you like. Economic integration was and is an important tool, but was not and is not the objective.
I constantly found, when I was Ambassador in Paris, that French people were capable of being very angry about the latest idiocy from the Commission or the European Court, and at the same time firmly persuaded that a strong European Union was in France's interests.
Seen from the other side of the Channel, Brexit looks like an incomprehensible decision to walk out of an institution which other members of the EU still regard as central to their future. It is not that they are putting politics before prosperity. They are putting other priorities ahead of Brexit: consolidating the signs of improvement in the European economy and dealing with the issues that really worry public opinion like migration and terrorism. On Brexit, their aim is to put it behind them as soon as possible, while avoiding damage to the integrity of the EU. Hence the hard line on money and on not allowing Britain to have their cake and eat it over the single market and the customs union. They have no interest in a bespoke deal which could encourage others to cherry-pick among the obligations of EU membership.
From my experience of working in EU countries, the politics and the prosperity are integrally linked. If the aim of the Berlin speech was to prompt German industry to pressure the German government to give Britain a new, specially privileged status in the single market, then it is destined to fail. However good the one-liners.