John O’Sullivan documents for National Review Online a key challenge for those who want Great Britain to remain within the European Union.

At the end of the first full week of the Brexit referendum campaign, things are not going well for the government-supported “Remain” camp led by David Cameron. That is not so much because the “Leave” campaign is ahead in the polls — it is in some polls, but that means little 18 weeks before the referendum — as because the basic calculations underpinning “Remain” are crumbling fast.

Essentially there is one large theme being pushed by “Remain.” It is popularly known as “Project Fear.” As its names implies, it is designed to make voters worry about Britain’s future if it leaves the European Union. It was tested in the Scottish referendum campaign when the Scottish voters were told: “Don’t risk it. Scotland can’t survive outside the United Kingdom. It’s too small, too reliant on subsidies from the English taxpayer, and too dependent for its own revenue on the high but unstable price of oil.” The strategists who crafted “Project Fear” think it succeeded then and will succeed in 18 months.

What actually happened is more complicated than that. As the referendum campaign wore on, Scots became disgusted with the crude defeatist and materialist nature of this appeal. Some thought “we’re better than that; we could cope.” The polls tightened almost to a dead heat. That alarmed other Scots, who thought “we’re better than that; we’re not in the U.K. just for English money.” They rediscovered a strong traditional U.K. patriotism and rallied to the Union. Opinion swung back. In the end, Scotland rejected independence by ten points.

Now, examine the various ways in which Brexit is more difficult political terrain for Project Fear than was the Scottish referendum:

(1) Britain is more than ten times as large as Scotland. Indeed, it is the fifth largest economy in the world. If it can’t survive (and indeed prosper) outside a European Zollverein, then neither can about 180 other nations in the world. In reality Australia, New Zealand, Canada, Singapore, and India are all smaller economies than the U.K. and all significant members of the G20. On that argument Project Fear doesn’t pass the smell test — or any more rigorous test either.