Back in May, when Donald's Trump's stunning U.S. presidential election victory seemed the remotest of possibilities, a senior European official took to Twitter before a G7 summit in Tokyo to warn of a "horror scenario".
Imagine, mused Martin Selmayr, the head of European Commission President Jean-Claude Juncker's cabinet, if instead of Barack Obama, Francois Hollande, David Cameron and Matteo Renzi, next year's meeting of the club of rich nations included Trump, Marine Le Pen, Boris Johnson and Beppe Grillo.
A month later, Britain shocked the world by voting to leave the European Union. Cameron stepped down as prime minister and Johnson - the former London mayor who helped to swing Britons behind Brexit - became foreign minister.
Now, with Trump's triumph over his Democratic rival Hillary Clinton, the populist tsunami that seemed outlandish a few months ago is becoming reality, and the consequences for Europe's own political landscape are potentially huge.
In 2017, voters in the Netherlands, France and Germany - and possibly in Italy and Britain too - will vote in elections following the triumphs of Trump and Brexit, and the toxic politics that drove those campaigns.
The lessons will not be lost on continental Europe's populist parties, who hailed Trump's victory on Wednesday as a body blow for the political mainstream.
"Today the United States, tomorrow France," French National Front founder Jean-Marie Le Pen, the father of the party's leader Marine Le Pen, tweeted.
Daniela Schwarzer, director of research at the German Council on Foreign Relations (DGAP), said Trump's bare-fisted tactics amounted to a model for populist European parties in the looming campaigns.
"The broken taboos, the extent of political conflict, the aggression that we've seen from Trump, this can widen the scope of what becomes thinkable in our own political culture," Schwarzer said.
Early next month, Austrians will vote in a presidential election that could see Norbert Hofer of the Freedom Party become the first far-right head of state in western Europe since World War Two.
On the same day, a constitutional reform referendum on which Prime Minister Renzi has staked his future could upset the political order in Italy, pushing Grillo's left-wing populist movement 5-Star closer to the reins of power.
Right-wing nationalists are already running governments in Poland and Hungary. In western Europe, the likelihood of a Trump figure taking power seems remote for now.
In the parliamentary democracies that exist in many European countries, traditional parties have banded together to form coalitions to keep out the populists.
But the lesson from the Brexit vote is that parties do not have to be in government to shape the political debate, said Tina Fordham, chief global political analyst at Citi, citing the anti-EU UK Independence Party which has just one seat in the Westminster parliament.
"UKIP did poorly in the last election but had a huge amount influence over the political dynamic in Britain," Fordham said. "The combination of the Brexit campaign and Trump have absolutely changed the way campaigns are run."
As support for traditional parties erodes and new political movements emerge, the challenge of forming coalitions and holding them together has becoming increasingly fraught.
In Spain, incumbent Mariano Rajoy was returned to power last week but only after two inconclusive elections in which voters fled his conservatives and their traditional rival on the left, the Socialists, for two new parties, Podemos and Ciudadanos.
After 10 months of political limbo, Rajoy finds himself atop a minority government that is expected to struggle to pass laws, implement reforms and plug holes in Spain's public finances.
The virus of political fragility could spread next year from Spain to the Netherlands, where the far-right Freedom Party of Geert Wilders is neck-and-neck in opinion polls with Prime Minister Mark Rutte's liberals.
For Rutte to stay in power after the election in March, he may be forced to consider novel, less-stable coalition options with an array of smaller parties, including the Greens.
In France, which has a presidential system, the chances of Marine Le Pen, leader of the far-right National Front, emerging victorious are extremely slim.
The odds-on favourite to win the presidential election next spring is Alain Juppe, a 71-year-old centrist with extensive experience in government who has tapped into a yearning for responsible leadership after a decade of missteps from Francois Hollande and Nicolas Sarkozy.
But in a sign of Le Pen's strength, polls show she will win more support than any other politician in the first round of the election. Even if she loses in the second round run-off, as polls suggest, her performance is likely to be seen as a watershed moment for continental Europe's far-right.
It could give her a powerful platform from which to fight the reforms that Juppe and his conservative rivals for the presidency are promising.
In Germany, where voters go to the polls next autumn, far-right parties have struggled to gain a foothold in the post-war era because of the dark history of the Nazis, but that too is changing.
Just three years old, the anti-immigrant Alternative for Germany (AfD), has become a force at the national level, unsettling Chancellor Angela Merkel's conservatives, who have been punished in a series of regional votes because of her welcoming policy towards refugees.
Merkel could announce as early as next month that she plans to run for a fourth term, and if she does run, current polls suggest she would win.
But Merkel would do so as a diminished figure in a country that is perhaps more divided than at any time in the post-war era.
Even Merkel's conservative sister party, the Bavarian Christian Social Union, has refused to endorse her.
Her only option for retaining power may be in another partnership with her traditional rival, the centre-left Social Democrats, a combination that was once considered anathema but has now become the norm.
She would face an emboldened opposition, with the AfD expected to enter the Bundestag for the first time.
"The great stability of the German political system in the post-war era was built on its two large moderate parties," said Schwarzer of the DGAP.
"But if the current trend continues, even 'grand coalitions' may not have enough support to rule anymore."