Well, that didn't take long.

The cheering and open arms as refugees and migrants flowed into Germany seem a distant memory, although it was only in October of last year.

Now the unseemly scramble is on — to block them, to send them back, to buy off the Turkish government to keep them there.

The trigger in Germany for this mounting backlash took place in Cologne on New Year's Eve.

Crowds gathered in front of the city's cathedral and train station. By mid-evening the troubles had started. Roving bands of men, many drunk, were groping, often violently, and robbing women who had come to celebrate the end of 2015.

Within days there were almost 600 complaints lodged with the police, and then signs across Europe that this was not an isolated incident. And the hue and cry against the flood of refugees began.

Right-wing activists were the first into the verbal battle. The Alternative for Germany party has been steadily rising in the polls with its anti-European Union and anti-refugee stance.

One of its leading lights, Björn Höcke, wrote on Facebook: "The events at the Cologne train station on New Year's Eve gave our country a taste of the looming collapse of culture and civilization."

As the chorus swelled, the governing party joined in. The German justice minister talked of "organized crime." Government officials said the law would be changed to make it easier to deport failed asylum seekers.

A leader of the governing Christian Democratic Union — Angela Merkel's party — said 1,000 undesirables should be deported each week.

We told you so

Lost in the shouting was the fact that almost all of those arrested or identified after the attacks of New Year's Eve were not from Syria and not refugees.

Most were from Morocco and Algeria. Many had been in Germany for years, using false identity papers. The German authorities didn't talk about them, let alone deport them.

But that, for the politicians, was an unimportant detail. The tide had turned and Chancellor Merkel's upbeat message about the new arrivals being a plus for Germany is now mocked or denounced.

It should be noted that the tide hadn't turned in the EU countries of East Europe. There it had never come in.

The leaders of Hungary, Slovakia, the Czech Republic and Poland were adamant from the beginning that they wanted no refugees at all. Cologne gave them new ammunition.

"This is what happens when you let migrants in," said Robert Fico, the Slovak prime minister.

Czech President Milos Zeman went him one better. "I think the whole invasion is being organized by the Muslim Brotherhood — with financial support from a number of states."

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Opponents of the anti-immigration right-wing movement protest against a PEGIDA rally in Cologne on Saturday. (Wolfgang Rattay/Reuters)

Even the traditionally open Scandinavian states have begun locking their gates.

Sweden, which has taken in more than 160,000 refugees, said enough was enough and imposed border controls.

Denmark went further. Its new right-wing coalition has proposed a bill that would strip refugees asking for asylum of most of their cash and oblige them to pay for their room and board while they waited for a decision on whether they could stay.

A similar policy in the Czech Republic, imposed in the fall, was denounced by the UN Commissioner for Human Rights. But who was listening?

The Danish prime minister had a more foundational plan: abolish the 1951 UN Convention on Refugees.

National 'purity'

And we haven't even got to France, where two murderous attacks in Paris have turned the capital into an armed camp, patrolled by police and soldiers.

French President François Hollande is determined to push through a constitutional amendment to allow his government to strip any dual citizen of his French citizenship if convicted of terrorist offences.

That was a non-starter for Stephen Harper in the recent election campaign. But in France, where fear now rules, it has overwhelming public support, even if the French justice minister admits it would have almost no impact in the fight against ideological killers.

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Time magazine's 'Person of the year,' largely for her generous welcoming of Syrian and other asylum-seekers, German Chancellor Angela Merkel has been much more on the defensive of late. (Michaela Rehle/Reuters)

Much of the rhetoric and some of the measures are astounding. What they testify to is a breakdown of the consensus that has allowed the European Union to grow and intensify its internal links.

That consensus owes much to a largely-forgotten calamity in the wake of the Second World War that saw one of the most ferocious episodes of ethnic cleansing in history.

It was not Hitler's doing, but that of the Allied leaders, notably Stalin and Churchill.

Their determination to rewrite the map of Europe and to punish the losers meant that no fewer than 12 million ethnic Germans became refugees, from what was then eastern Germany (handed over to Poland and the Soviet Union), and from Poland and Czechoslovakia.

In addition, hundreds of thousands of others — Poles, Ukrainians, Slovaks, Hungarians — were also ejected from their homes and forced to walk to other lands.

When the dust had settled the melting pot of Central Europe had disappeared, replaced by countries that were, by and large, ethnically "pure."

Over the decades that has basically not changed, though further west, France took in millions of North Africans, mostly Muslims from its former colonies, to build its cars and sweep its streets.

The strain of integrating, or rather not integrating, that population can be traced in the rise of the anti-immigrant National Front, which gathered in almost 30 percent of the vote in the first round of the recent regional elections.

It also preaches national purity, code for removing the Muslims, although, since a large number of them were born in France and have French citizenship, the National Front doesn't offer details on mass deportation.

Now even the Germans, with their millions of Turkish "guest workers," and the Scandinavians, seem to yearn again for national purity.

The goal is unachievable, but the demand for it is already creating enormous cracks in the foundations of the European Union. Those cracks will widen; the edifice could well crumble.