I’ve spent a good part of the past three decades studying Britain’s relations with Europe. In fact, I wrote my thesis on Britain’s first application to the EEC, the European Union’s predecessor.

Being in Britain for the referendum was a joy. It was also a lesson. I watched the last week of the referendum campaign from London. That may have been a mistake – not the watching, but London. I would have learned more in Yorkshire.

As it turned out, the referendum was, among other things, a vote against London’s view of the European Union. By staying in London, I missed a chance to meet the people who won the vote for Brexit, the people of northern England.

Of course, every vote counts. But if Brexit hadn’t rolled up big majorities up north, it would have lost to the combination of Scotland and central London.

I dare say a lot of commentators made the same mistake I did: not going north of Islington. And I missed something else. Though I have friends in Labour, I move more in Tory circles. And even my Labour friends are Blairites.

I knew there was a long tradition of working class dislike of the EU and its predecessors – exemplified by Ernest Bevin, one of my heroes. But again like a lot of commentators, I hadn’t fully grasped that this tradition is still alive. It would be a huge mistake to view the referendum’s outcome as a Tory victory. It was Tory splits, and the rise of Ukip, that got Britain its referendum. But it was Labour votes what won it.

At the last General Election, Ukip and the Tories together polled just under 50 per cent of the vote – 49.5 per cent, to be exact. Together, that’s not a majority, even if they all backed Brexit. And of course, they didn’t: a sizable minority of Tories, and even a few Kippers, were Remain.

Leave could only win by taking almost half Labour’s 2015 vote. Of course, Britain invented the study of elections: its psephologists will have a field day with Brexit. But it seems, ironically, that a campaign often denounced as divisive was actually dominated by cross-party voting.

I admit I have trouble taking that charge of divisiveness seriously. You can’t have a meaningful campaign without real disagreements.

What people usually mean when they say something is divisive is that you should stop arguing and agree with them. It’s a tactic intended to win the argument by making you feel bad.

Remain really didn’t want immigration to be an issue in the referendum, because they simply had no answer for it: as long as Britain was in the EU, it couldn’t control how many EU citizens arrived in Britain looking for work. And a lot of people in Britain didn’t like that very much.

The only way to deal with the issue was to try to delegitimise it. But talking about the right of a nation to decide who migrates here, who can take a job, and who gets benefits isn’t wrong.

If you want to be a nation, you have to be willing to make a distinction between who has the right to be there, and who receives the privilege of being there. You have to be willing to accept that there’s a difference, and that there should be, between citizens and foreigners.

Though admittedly, when it came to this referendum, that difference didn’t amount to a lot: pretty much everyone got involved, from Barack Obama to the IMF. And I daresay that did affect the outcome, though not quite as Obama and company intended it to.

One of the Labour Party’s excuses for losing is that this was a protest vote against Tory austerity. A universal explanation, and therefore valueless: for Labour, everything’s about Tory austerity. I’d point a finger at good old-fashioned bloody-mindedness instead.

A lot of people dislike the EU because they see it as foreign and out of touch. It’s not obviously the best strategy to ask other out of touch foreigners to make the case for it. That’s unlikely to change minds: it’s more likely to convince the doubters that they were right all along.

What’s next for Brexit? Well, of course there’s Article 50, and the job of finding a new Prime Minister. But I think that, for some, Brexit will be the new global warming: an explanation for everything that goes wrong, or that they just doesn’t like. The EU’s true believers aren’t going to stop believing in it. What they are going to do is start blaming Brexit. Putin invades the Baltics? Brexit’s to blame. A recession? That’s Brexit for you.

Back in the real world, Brexit does bring a new challenge. One reason most politicians like the EU is that it allows them to shift the blame to Brussels. Well, British politicians won’t have that excuse any more. Neither will anyone else in Britain.

That means it’s more important than ever for Britain to make good choices, because from now on, if you get it wrong, it’s your fault. In the 1960s and 70s, Britain made a lot of mistakes, lost its confidence (and the Empire), and stumbled into Europe as a result.

I don’t believe that will happen again. One advantage of making mistakes is that you can learn from them. And Britain’s not just recovered its freedom from Brussels. It’s shown it has the confidence to make tough choices. And for this American, that means one thing. Britain is back.