WASHINGTON -- A rare phenomenon is transpiring in a foreign capital where mentioning Canadian politics is generally about as likely to stimulate conversation at a dinner party as to get you disinvited from the next one.

People are curious about Canada's next prime minister.

It's evident on multiple fronts in Washington -- from conversations in cabs and coffee shops, in government offices and think-tanks, in media stories, and from foreign politicians looking to learn about Justin Trudeau.

During a U.S. visit, the leader of a centre-left European political party revealed he was reading a book about the recent history of Canada's Liberals and expressed hope of eventually meeting Trudeau.

"Fascinated," is how Diederik Samsom described his reaction to the Canadian election.

The history of his party will sound familiar to Canadian Liberals. Traditionally mighty, recently struggling, the Dutch Labour party swerved left in the 1970s; spent the 1980s in opposition; tacked back to the right in a governing coalition in the 1990s; and has since fallen on hard times, as rivals to its left and right eat away at its support.

So it's no coincidence that he's asking questions about the campaign that pulled Canada's centre-left party from third place to a surprising majority.

He's not alone.

Inside the unofficial think-tank of the U.S. Democratic party, the Liberals' winning election playbook is being analyzed and its lessons shared with left-leaning parties around the world.

Matt Browne has prepared a briefing paper on the Liberal win for allies in different countries where he's heard curiosity or seen applicable lessons -- including the U.K., Denmark, Holland, France, Italy and Germany.

"It's been a pretty amazing week or so," Browne said in an interview. "Amongst the progressive community in particular, people have been trying to figure out what the lessons of this are."

He works on international partnerships at the Center for American Progress, founded and run by high-ranking figures in Democratic politics. Some of its senior members had met Trudeau and his team in opposition and they offered congratulations on the Liberal election victory.

Browne identifies three lessons from Trudeau's win:

Defending deficits. Browne said too many progressive parties shrink from fiscal debates, and wind up timidly adopting the austerity language of their opponents. But he said Trudeau took a chance on challenging the balanced-budget orthodoxy, and promoted the idea of good debt (for infrastructure) versus bad debt. He said it worked, and it could work in Europe too.

Defending diversity. Amid tea party anger over illegal migrants in the U.S., and a heated European debate over Syrian refugees, Browne said attempts to tap into suspicion of foreigners failed in Canada. The Liberals rejected limits on niqabs, the barbaric-practices hotline, and the characterization of Syrian refugees as a threat: "Embracing diversity as a strength, versus identity politics. Pushing back against Islamophobia," Browne said. "I think (people) felt that that was something to be admired."

Optimism. A willingness to wander into crowds, engage on social media, and generally remain cheerful: "A politics where people are competitors, not enemies... There were echoes of Obama in that -- the desire to move beyond red state and blue state."

One big difference with Obama, he noted, is that Trudeau arrives with a comfortable parliamentary majority and won't have to fight for votes to get his agenda passed.

The foreign coverage has emphasized different aspects of Browne's three lessons.

Columns in the Guardian and New York Times mentioned the deficit spending.

In a piece titled, "Keynes Comes to Canada," Paul Krugman wrote that, "Canada has surprisingly often been the place where the future happens first. And it's happening again... (Trudeau) has an opportunity to show the world what truly responsible fiscal policy looks like." The Guardian's William Keegan wrote a piece titled, "Cameron falters but Canada understands: we need Keynes."

Some economists will grumble with the accuracy of the analysis -- arguing that Conservatives in Canada clearly practiced Keynesian economics, by drastically expanding spending during the 2009 recession and then withdrawing it as the economy returned to safer ground.

CNN's Fareed Zakaria touched on the cheerfulness theme. He began his Sunday show by referring to the angry politics of the day, marked by the left-wing populism of Bernie Sanders and the right-wing populism of Donald Trump.

But he said populists generally lost throughout American history to rivals who embraced open trade, free markets, cultural diversity and regulated capitalism.

Zakaria quoted a line from Trudeau's victory speech: "One could imagine FDR in the depths of the Depression, cocking his head up, with his cigarette-holder jutting skyward, saying, 'Sunny ways, my friends, sunny ways."'

Plenty of the foreign coverage, and some of the Washington chatter, has been about the physical appearance of Canada's new power-couple. Paris Match magazine ran a glamour-shot cover photo of the Trudeaus.

The accompanying story compared the phenomenon to the what-if scenario of John F. Kennedy Jr. succeeding JFK. It described the enthusiasm of Liberal crowds to those from the first campaigns of Barack Obama and Tony Blair.

A Washington think-tank that analyzes Canadian affairs has detected a spike in attention.

"I've already had more Americans ask me about the Canadian election in the week since than they did for the entire previous 78 days," said Andrew Finn of the Wilson Center's Canada Institute.

But he said the U.S. interest might have more to do with other factors: familiarity with Trudeau's family name, and more interest in foreign elections in a non-election year in the U.S.