In a stunning victory for the "Leave" campaign, Britain has voted to exit the European Union. Here's what happens next. (Jason Aldag,Adam Taylor/The Washington Post)

In a stunning victory for the "Leave" campaign, Britain has voted to exit the European Union. Here's what happens next. (Jason Aldag,Adam Taylor/The Washington Post)

The “leave” campaign won the referendum on withdrawing Britain from the European Union because the arguments on which the “remain” side relied made leave’s case. The remain campaign began with a sham, was monomaniacal with its Project Fear and ended in governmental thuggishness.

The sham was Prime Minister David Cameron’s attempt to justify remain by negotiating E.U. concessions regarding Britain’s subservience to the E.U. This dickering for scraps of lost sovereignty underscored Britain’s servitude and achieved so little that Remainers rarely mentioned it during their campaign.

Project Fear was the relentless and ultimately ludicrous parade of Cassandras, “experts” all, warning that Britain, after more than a millennium of sovereign existence, and now with the world’s fifth-largest economy, would endure myriad calamities were it to end its 23-year membership in the E.U. Remain advocates rarely even feigned enthusiasm for the ramshackle, sclerotic E.U. Instead, they implausibly promised that if Brexit were rejected, Britain — although it would then be without the leverage of the threat to leave — would nevertheless somehow negotiate substantially better membership terms than Cameron managed when Brexit was an option.

Voters were not amused by the Cameron government’s threat of what critics called a Punishment Budget to inflict pain on pensioners (e.g., no more free bus passes) and others because Brexit might cause the gross domestic product to contract 9.5 percent and home prices might plummet 18 percent. Voters did not like being told that they really had no choice. And that it was too late to escape from entanglement in the E.U.’s ever-multiplying tentacles. And that the very viscosity of the E.U.’s statism guarantees its immortality.

Voters chose the optimism of Brexit. Sixty years after Britain’s humiliation in the Suez debacle, Britain has a spring in its step, confident that it will flourish when Brussels no longer controls 60 to 70 percent of the British government’s actions. Britain was last conquered by an invading army in 1066. In 2016, it repelled an attempted conquest by the E.U.’s nomenklatura .

By breaking the leftward-clicking ratchet that moves steadily, and only, toward more “pooled” sovereignty and centralization of power, Brexit refutes the progressive narrative that history has an inexorable trajectory that “experts” discern and before which all must bow. The E.U.’s contribution to this fable is its vow to pursue “ever-closer union.” Yes, ever .

To understand why Brexit could and should be the beginning of an existential crisis for the E.U., look across the English Channel, to France. There, King Clovis recently was invoked 1505 years after his death in 511.

Before a particular battle, Clovis promised that if the God to whom his Christian wife prayed would grant him victory, he would become a Christian. He won the battle and converted. Recently, Nicolas Sarkozy, France’s once and perhaps future president, said France was “born of the baptism of Clovis,” it has a Christian tradition and remains “a country of churches, cathedrals, abbeys and shrines.”

Actually, 71 percent of the French say religion is unimportant to them and fewer than 4.5 percent attend weekly church services. But Sarkozy was aligning himself with the palpable desire in France and elsewhere in Europe to resist the cultural homogenization that is an intended consequence of the E.U.’s pressure for the “harmonization” of the laws and policies of its 28 disparate member nations.

In Paris these days there are marches by a group called Generation Identitaire, described as the “hipster right.” It aims to rally “young French and Europeans who are proud of their . . . heritage.” A recent statement on its website declared that “Islamist attacks” and “the migrant invasion” made 2015 “a turning point in the history of our country.” The statement continued: “The French have been silent for too long. . . . It is time to show our determination to live on our land, under our laws, our values and with respect to our identity.” Sarkozy, the son of Greek and Hungarian immigrants, sympathizes.

Euroskepticism is rising dramatically in many E.U. nations. There might be other referendums. Or the E.U. might seek to extinguish this escape mechanism. A poll in Sweden indicated that it might follow Britain out. In France, there could be a campaign for Frexit.

Such was the remain side’s intellectual sloth, it wielded the threadbare aspersion that advocating withdrawal amounted to embracing “isolationism.” Actually, Brexit was the choice for Britain’s international engagement as a nation . The revival of nationhood is a prerequisite for the reinvigoration of self-government through reclaimed national sovereignty. Hence June 23, 2016, is now among the most important dates in postwar European history.

1 of 56 Full Screen Autoplay Close Skip Ad × Britons react to cutting ties with the European Union View Photos Many celebrated the referendum results Friday, and British Prime Minister David Cameron announced that he will resign after Britons went to the polls the day before. Caption In late June, many celebrated the referendum results, and British Prime Minister David Cameron announced that he will resign after Britons went to the polls. June 26, 2016 People walk over Westminster Bridge wrapped in Union Jacks, toward the Queen Elizabeth Tower (Big Ben) and the Houses of Parliament in central London. Odd Andersen/AFP/Getty Images Buy Photo Wait 1 second to continue.

Read more from George F. Will’s archive or follow him on Facebook.