Fear of others drove the Brexit vote—and it could happen here.

At the security check at JFK Airport in New York, I inadvertently got between a German man and his wife. “You go ahead,” I told him. “But you are first,” he replied with Prussian punctiliousness. So I played my trump card: “We Europeans must stick together.”

He smiled. “Let’s hope we do. We all want you to stay.” That was the last conversation I had as a European, an identity I’d acquired officially along with a British passport a year ago, but one which felt at least as precious as any piece of paper. My Europe was a continent with a bloody past but a brilliant future, where language and literature and food and wine and film and theater were all enriched by a culture that looked confidently outward, and a political settlement that not only kept the peace for over half a century, but acted as a powerful magnet pulling countries on the periphery toward the European political norms of democracy and civility. I landed the next morning in London, capital of a nation that voted to turn its back on its neighbors.

There are people who will tell you the reasons for that rejection are complex; two weeks ago, I would have been one of them. For decades, the press here have used Brussels as shorthand for an overweening, undemocratic bureaucracy. There has been truth in that depiction, from fruit-and-vegetable stands penalized for selling in pounds and ounces, to a recent court decision barring Scotland’s minimum price on alcohol as a way to deter binge drinking. It was also horribly clear that whatever lessons might have been learned watching the burning of Sarajevo and the slaughter in Srebrenica were long forgotten by the time Syria’s refugees came knocking.

Now, the fraudulent, racist, xenophobic Leave campaign has won, by a margin of 1.2 million votes. The English people have decided they do not want to be European any more.

Though the Leave campaign’s brilliant slogan, “Take Back Control,” was designed to suggest otherwise, it wasn’t about sovereignty or democracy.

This vote was about two things: a chance to register distrust and disgust with political elites, and a fear and hostility toward outsiders rooted in racism.

The political consequences were immediate. By lunchtime, Prime Minister David Cameron announced his resignation. The economic fallout will take longer to accumulate. Headlines screamed the pound sterling hit a 30-year low, and Britain’s paper economy lost £120 billion. Those effects will not be confined to this island nation. You can’t build a wall to keep in capital – or keep out ideas. Brexit has pulled a leg out from under the whole European project. The world’s largest free market has, overnight, become a less predictable place to do business.

Far more dangerous, though, is the example the British have set for the world of a post-factual democracy. To Americans tempted to think we are too smart to be led astray in similar numbers by our own demagogue, I can only say: The British thought it couldn’t happen here. And it just did.

D.D. GUTTENPLAN is The Nation’s Editor-at-Large.