Editor’s Note: Paul Hockenos is the author of “Berlin Calling: A Story of Anarchy, Music, the Wall and the Birth of the New Berlin.” The opinions in this article belong solely to the author.

CNN  — 

President Trump’s abrupt departure from the G7 summit on June 9 and puerile parting shots at Canada and Europe underscore a somber state of affairs that many believers in the transatlantic alliance had refused to accept, until now. Washington in the era of Donald Trump isn’t just an eccentric, out-of-sorts, old friend to Europe, but rather an opponent that wishes it harm.

The Europeans have no choice but to respond immediately, which means taking bold collective action to shore up the euro and the crisis-battered EU itself, their best defenses against the storm that is raging on multiple fronts.

This was evident long before last week. In fact, looking back at the highly undiplomatic barbs of the US’s top diplomat in Germany, the freshly-minted Trump appointee Richard Grenell, Trump’s actions in Quebec were even predictable. He sees one-time allies as enemies.

On June 3, Grenell, who’s been in office for all of a month, effectively announced in an interview with Breitbart that his mission in Germany is not that of a neutral diplomat at all, but rather of an agent of the alt-right’s conservative revolution, which luminaries like Breitbart’s editors want to promote beyond the U.S.’s borders.

Grenell unleashed an outcry in Europe by lavishly complimenting Austrian Chancellor Sebastian Kurz as a “rock star” among Europe’s politicians, and then meeting with the controversial Christian Democratic politico in Germany. Kurz is currently heading up a coalition with the far-right Freedom Party, which ran on a xenophobic platform. Kurz takes a considerably harder line on immigration than German Chancellor Angela Merkel, and is friendly with Vladimir Putin and Hungarian strongman Viktor Orbán.

Grenell broke with decades of diplomatic tradition — it’s considered poor form for ambassadors to directly comment on the internal politics of their host countries — by saying that he intended to “empower other conservatives throughout Europe.” He added: “I think there is a groundswell of conservative policies that are taking hold because of the failed policies of the left.”

In terms of “conservatives,” the new ambassador was obviously referring not to mainstream conservatives of Merkel’s stripe, as they are in decline throughout Europe. He meant the likes of Kurz, and although he didn’t mention other names, Kurz’s fellow travellers include Orban, Poland’s ruling arch-conservative Law and Justice Party, and now Italy’s new coalition government, which includes in government the far-right League Party. Others that fall in that category include the racist, nationalist, and EU-skeptic National Front in France, The Netherlands’ Party for Freedom, and Germany’s Alternative for Germany.

Like Putin and Trump, these parties and their leaders are proudly illiberal and staunchly anti-immigrant, dismissive of democratic checks and balances, in favor of expansive armies and committed to law and order. Their distrust of alliances and supranational governance is couched in criticism of a distant, controlling Brussels. But their vision of a “Europe of nations” spells the end of the EU, for it cannot work as a loose alliance of independent nation states with competing values and different models of governance.

The EU’s own strongmen may not fully realize that they’re provoking the EU’s disintegration. After all, they say that they want to remain in the EU. Their countries gain from the EU financially. And their populations are strongly pro-EU. What they don’t realize is that by throwing a spanner in its works, they could sink it. They already hinder the EU from acting effectively in many areas, including international affairs.

This misguided quest for “another kind of EU,” however, isn’t what Putin or Trump’s ideologues want. They’re plotting the EU’s demise, which serves their own political purposes.

For one, the stronger the national populist movements elsewhere in the world, the less their own campaigns look out of step, unreasonable, or radical. They shift the mainstream to the right.

But perhaps even more importantly, Putin and Trump wish these like-minded nativist forces in Europe well so that they’ll paralyze the EU. They want their defiant, jingoistic arch-conservatism to sow discontent and confusion on the continent. They want them to weaken the EU, which Putin and Trump, in their zero-sum worldviews, see benefiting them. By breaking the EU, they are undermining the Europeans – their opponents.

Indeed, by undercutting stability and multilateralism they can change the face of the postwar world order, sending it back to the years before and between the world wars, when Europe was a theater of constantly shifting alliances where might made right. The products were the most destructive wars of the 20th century.

The geostrategic implications of Trump’s embrace of the European far right are vast: the postwar transatlantic alliance is effectively defunct. The old rules no longer apply, and no quantity of indignation on behalf of the Europeans will reconstitute them.

Europe’s response is crucial, for it must step up to the bullying tyrants on their borders and defeat the illiberal forces surging at the ballot boxes at home. France and Germany are increasingly alone in this battle.

Germany, which should be at the front of a counter strategy, is actually part of the problem as Merkel has neither the vision nor the clout to respond as history is calling her to do. All too often, she has treated the EU as a vehicle for Germany’s short-term interests, and now Germany is paying the price.

She must endorse the EU as passionately as Macron has, and convince Germans and Europeans beyond Germany that the EU has brought them unparalleled prosperity, peace, and much more. Just a week ago, for example, the EU instituted the strongest data privacy laws in the world. Europe enjoys the highest consumer protection standards on the planet. The list is long but you don’t hear it from Merkel and most of her peers across the continent. The only way to beat them back it to confront them with better arguments and policies.

As for the likes of Grenell, evicting him from the country would only serve the far right’s purposes, enabling it to portray Europe’s “elites” as high-handed and undemocratic. Rather, Berlin should simply give him the cold shoulder, which is exactly what Merkel appears to be doing.

One day, hopefully soon, he’ll leave. But the Trump administration will be leaving wreckage behind that a new administration won’t be in a position to repair so quickly. The Europeans have to fill the void now.

Note: This article has been updated to clarify that far-right parties in France, the Netherlands and Germany share ideological themes with parties in other nations such as Austria and Italy, but they have not have received the support of US Ambassador Richard Grenell.