The biggest loser of Brexit will not be the UK or the EU. It will be the idea of a Europe whole, free and at peace. There is still time for the two parties to change course. But not for long.

John Maynard Keynes, arguably the most influential economist of the 20th century, attended the Paris peace negotiations at Versailles in 1919 as a delegate of the British Treasury. He did not like what he saw. Instead of the victorious powers trying to integrate Germany back into the European economy, they were determined to make Germany pay a price for its bad behaviour.

In his subsequent book, The Economic Consequences of the Peace, Keynes argued for a more generous peace. Imposing harsh conditions on Germany, he said, would only lead to economic misery, hurt national feelings and an insecure future for Europe.

His message was not heeded. Germany was humiliated. Its economy was ravaged. Its people were condemned to poverty. It took another world war for Europe to realise the way forward was not for the strong to impose harsh conditions on the less powerful. The way forward was to build an inclusive Europe where every state could participate on its own terms.

Listening to Michel Barnier, the EU’s Brexit negotiator, it seems as though we are back in Versailles. Instead of the EU trying to integrate the UK into a mutually beneficial trade agreement, it is adapting the approach the victorious powers used at the 1919 Paris negotiations. Since it was the UK who started this madness, it will have to pay. Since the EU has the stronger cards, it will call the shots. Will London continue as a financial centre in a post-Brexit Europe? Brussels will decide. When can the UK start negotiating new trade deals? Brussels will decide. How much will the UK pay for the privilege of leaving the club? Brussels will decide.

The British are not making Mr Barnier’s job any easier. David Davis, the UK’s Brexit negotiator, has called his counterpart “silly”. Mr Davis’s colleague Liam Fox, trade secretary, has accused the EU of blackmail. EU citizens in Britain complain about being treated as second-class citizens. The UK’s position papers are strong on ambition but weak on details. Instead of rising to the occasion, British leaders are dragging their feet. There is no vision, there is no leadership.

It does not have to be this way. There are examples of amicable divorces. And there are plenty of examples in European and world history where the more powerful have been generous with countries that have wrecked the existing order.

The EU should look at the Congress of Vienna (1814-15). Napoleon had caused havoc in the European continent, yet France was allowed back into the family of states. A long period of peace followed. The EU should also remember how Germany was treated after the second world war. Rather than repeat the mistakes of 1919, the victorious powers heeded Keynes’ advice and sought to reintegrate Germany. A long period of peace followed.

As for which historical examples the UK should be studying, here are two suggestions: the exit of Singapore from the Federation of Malaysia and the break-up of Czechoslovakia. Both were fine examples of statecraft in the service of peace and prosperity.

When it became clear in 1965 that Singapore and the rest of Malaysia had to go separate ways, the leaders of both countries showed remarkable prudence. Lee Kuan Yew, the leader of Singapore, was distraught. But instead of complaining about the terms of the divorce, he set out to build a successful city-state.

In 1993, the leaders of the Czech Republic and Slovakia negotiated a deal in a matter of months, and all assets (including foreign embassies and military material) were divided in good order. Pragmatism prevailed. Recriminations were avoided.

It is not too late for the EU and Britain to learn from history. But time is running out. Brussels and London must both do what is good for Europe and stop playing a zero-sum game.

The writer is secretary-general of Northern Light, a European business leaders’ convention, and CEO of Nordic West Office

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