It seems an ice age since Prime Minister Justin Trudeau and Germany's Angela Merkel were anointed the last defenders of the liberal international order.

But it was actually only weeks ago, in December. And their anointer, then-U.S. vice-president Joe Biden, is now yesterday's news. On Saturday, Merkel meets his replacement, Mike Pence, marking the first time she sits across from a member of President Donald Trump's inner circle.

First, though, the German chancellor briefly plays host to Trudeau — who's already met Trump himself — to compare notes on what's come in the past 30 tumultuous Trump days, and what's yet to come.

Notwithstanding Canada's proximity to the U.S., however, it is Merkel and Germany who stand at the front line in the battle to defend the familiar world order.

German Chancellor Angela Merkel presents a photo to Prime Minister Justin Trudeau Thursday showing him posing with his father Pierre Trudeau when he was 10 years old in Berlin. (Guido Bergmann/Getty Images)

At the core of her battle plan seems a determined effort to push back against Trump's isolationist views.

"No country can solve the problems alone," she said again this week, seemingly in response to Trump's America-first philosophy. "Joint action is more important."

With Trump, Brexit, Russia, the migration crisis and the rise of populist movements all challenging that view to varying degrees, just about everything Merkel does is coloured by her fight back: even her bid for re-election.

The three-term chancellor is really fighting two significant opposition campaigns ahead of the ballot in September: one involves her opponents at home, including, notably, an increasingly potent far-right party. The second is a sustained disinformation campaign, believed to originate in Russia, aimed at discrediting her.

She isn't alone in this — it seems almost every upcoming European election campaign is being targeted by barrages of increasingly outlandish fake news — but Merkel's still-vocal defence of "Western values" seem to make her the prime target of such challenges from outside.

German Chancellor Angela Merkel, right, greets Prime Minister Justin Trudeau on his arrival before a meeting at the Chancellery in Berlin on Friday. (Odd Andersen/AFP/Getty Images)

Still, at this weekend's Munich security conference, Merkel will relaunch her defence. And despite Pence's apparent plans to reassure allies of U.S. commitment, she will reportedly focus that defence on the relationships that have organized the world for much of recent history — that all-important transatlantic relationship and the post-war multilateral institutions, such as NATO. And of course, the European Union.

This is an area where she and Trudeau see eye to eye, but where her comparatively outsized role in world politics give her far more sway in defending that Western liberal order.

"Merkel is very worried about this," says Judy Dempsey, a non-resident senior fellow at Carnegie Europe and author of The Merkel Phenomenon. "I think that's why she's coming to Munich."

But while, as Dempsey says, "she does have influence," with Brexit looming, and many others in Europe echoing Washington's isolationist notes, Merkel at times seems a lonely voice in this neighbourhood.

Harshly critical

Germany is flanked by countries, including France, that are flirting with home-grown, populist, anti-EU elements. Among supporters of those movements Merkel is constantly bashed, not only for defending the EU, but for her response to the migration crisis, taking in an estimated one million asylum seekers in 2015.

The U.S. president, too, has been harshly critical of that policy. The same U.S. president who tried imposing an entry ban on the citizens of certain Muslim countries — and who has cast doubts on NATO and the EU.

Merkel has not been impervious to all this change in tone from neighbours and the U.S. She has since advocated efforts to stem the arrival of asylum seekers into Europe, for example.

But on defending western values, and multilateralism, she has been consistent, trying to push the EU closer together when many (in Europe, Russia, and the U.S.) would rather pull it apart.

Even among European leaders who support Merkel, there are those who "think, 'Oh, we can muddle through.' Well, we can't muddle through. Trump won't allow us to muddle through," says Dempsey.

"Merkel says we have to fix this."

Similar values

Trudeau, fresh from celebrating Canada's landmark trade deal with the EU, would agree. Merkel will have been happy to see him — a friend who espouses similar values and, unlike some of her European counterparts, isn't afraid of publicly defending them.

But Trudeau faces only a fraction of the challenges, and for now, has comparatively limited sway abroad in the Trump era.

So for Merkel, the hard work starts when he leaves, when she turns her attention back to the multitude of battles at her doorstep.

All those assumptions could change, though, if she loses the election in September.