The fact of our impending departure does not, however, mean cutting ourselves off from Europe.
If Brexit is easy to define, the details of what our post-EU relationship will look like are more complex. But it is already possible to see the outline shape of a likely deal.
First things first. An EU/UK trade deal that comes into effect at midnight on the day we depart might under the right terms be desirable – but it is not vital.
World Trade Organisation rules are a perfectly acceptable fall back position. WTO terms have, of course, served China, the USA, Japan, Australia, and a host of other countries which have managed to increase their exports to the Single Market faster from outside than we have from within rather well.
Like Boris Johnson, David Owen, Gisela Stuart and all of those involved in the official Vote Leave campaign, Brexit for me is an opportunity to make Britain more open, outward looking and globally competitive.
So yes, as Theresa May has made clear, the freedom of movement for people will end. A by-product of the Maastricht treaty, which created the idea of a common citizenship as well as currency, EU citizens will no longer have an automatic right to live and work in the UK.
But that does not mean that people from EU states will not be able to come to the UK to work here. Before we joined the EU, it was perfectly possible for British firms to hire employees from France or Italy or elsewhere. It should be so again once we have left.
I can easily imagine a work visa scheme, perhaps linked to national insurance numbers, which would free firms to hire workers from EU states – with one main proviso: that new employees could only be hired if they were paid a sufficiently high salary (£24,000 per annum?) to preclude the possibility that they might claim any in-work benefits.
Such a scheme would not only reduce low skilled migration. In doing so, it would tackle some of the factors that have contributed towards wage compression and the UK’s poor productivity performance.
We do not need the EU’s permission to put such arrangements in place – and it would be in our interest to have a generous work visa scheme irrespective of any deal we might strike with the EU. But I suspect such a scheme would make it easier to strike an agreement on the free movement of goods and services – or two parallel deals, to be more precise.
The EU has a massive trade surplus in goods with us, and therefore a massive incentive to strike a deal to maintain cross-Channel trade in goods from which they are the principal beneficiaries. A quid pro quo to such a deal on goods would be one on services.
Of course, in all the years that we were members, the EU never did get around to imposing a single set of standards for financial services. Nor should we seek any sort of standardisation now either. Instead we should look to a deal based on the mutual recognition of one another’s standards.
Incidentally, trade agreements based on mutual standard recognition are not only the way forward when dealing with the EU. It’s an approach that we are likely to see reflected in the free trade agreements we put in place with the rest of the world from 2019.
Months of posturing – not to mention electioneering in Germany, France and perhaps even Britain – lie ahead. But make no mistake. Any post-Brexit deal will be largely hammered out between Mrs May and her German counterpart. As everyone in Brussels secretly admits, Germany now calls the shots on all the big decisions – and we should ignore the posturing of various Eurocrats.
Having the grown-ups doing the deal increases the prospects of pragmatism prevailing.
It’s not only in terms of trade that we will need to cooperate. Theresa May will know better than almost anyone from her time at the Home Office about the importance of intelligence sharing. Our universities and other institutions must continue to collaborate across borders.
But rather like with Nato membership, when any formal agreements need putting in place it must be done on a bilateral basis, between the EU (or its member states) and the UK as equals. Never again under supranational law as a supplicant.