BERLIN — Since Jan. 20, 2017, European leaders have managed U.S. relations with one eye on the clock, anxiously counting down the hours until President Trump’s term is up and hoping the core of the Western alliance isn’t too badly damaged in the meantime.

But as Trump’s aggressive rhetoric toward America’s closest allies has evolved into hostile action this spring, a new fear has swept European capitals.

Trump may not be an aberration that can be waited out, with his successor likely to push reset after four or eight years of fraught ties. Instead, the blend of unilateralism, nationalism and protectionism Trump embodies may be the new American normal.

“It is dawning on a number of European players that Trump may not be an outlier,” said Josef Janning, head of the Berlin office of the European Council on Foreign Relations. “More and more people are seeing it as a larger change in the United States.” 

Even before Trump was elected, Europeans sensed that Washington’s traditional role as guarantor of the continent’s security and stability was slipping away, and that post-World War II ties were fading along with the generations that forged them.

But Trump’s seeming delight in smashing transatlantic bonds — and the lack of domestic constraints on his ability to do so — has signaled, Janning said, that the basis for Western strength and peace for 70-plus years “probably won’t come back.”

That carries serious implications for how Europe responds to Trump. Until now, key leaders have avoided open conflict with the U.S. president, trying instead to placate him or, at best, subtly persuade him. Above all, they have sought to preserve strong relationships at various levels within the U.S. government, if not with the man at the top of it, so there’s a foundation to build on after he is gone. 

European Council President Donald Tusk said May 16 that President Trump made Europe realize that "a helping hand" can only be found "at the end of your arm." (Reuters)

That is still the prevailing strategy. But a succession of adverse moves culminating in Trump’s decision to pull out of the Iranian nuclear deal has brought transatlantic relations to their lowest point since the 2003 invasion of Iraq, if not far longer.

If Trump is succeeded by a more traditional Democratic or Republican administration, the wounds could still heal. But, even then, it could take a long time, given the extent of the damage.

And close European observers of the United States are not optimistic about a reversion to the mean. 

They study the increasing polarization of U.S. politics and see less enthusiasm for transatlantic ties at either end of the political spectrum. They have also been repeatedly disappointed as one supposed brake after another on Trump’s most extreme foreign policy impulses — Congress, the president’s own advisers and popular opinion — has fallen away. Trump, they note, is alienating America’s closest allies, and the American public doesn’t seem to mind.

Europeans have begun to wonder aloud whether they need to respond accordingly. 

One sign of the evolving stance toward the United States was the unusually biting commentary this past week from European Council President Donald Tusk, whose job in Brussels is to channel the ids of the 28 nations in the European Union. A mild-mannered former Polish prime minister, his statements are typically gentle efforts toward consensus, not international rallying cries.

Not this time.

“With friends like that, who needs enemies?” Tusk told reporters as he readied a summit of E.U. leaders largely focused on Trump-ignited brushfires. The faltering Iran nuclear agreement, the bloodshed in the Gaza Strip and the specter of a transatlantic trade war were all on the agenda.

Tusk denounced “the capricious assertiveness of the American administration,” using terms that just 16 months ago would more typically have been applied to international rogue nations such as North Korea and Russia.

His sharp tone matches the public mood. In Germany, a country that rebuilt itself after World War II in America’s image and with American money, polls show that Trump is seen as a bigger threat than Russian President Vladimir Putin. 

More than two-thirds of Germans describe their country as moving away from the United States, and an equal number describe the relationship as “tense,” according to a survey released this past week by the Frankfurter Allgemeine newspaper.

After the U.S. pullout from the Iran deal, the influential weekly Der Spiegel called on Germany to become part of the “resistance against America” and pictured Trump on its cover as a yellow-haired middle finger to the continent.

Some of Europe’s anger reflects a long-standing current of anti-Americanism. But even fans of the United States say they are losing faith now that the country that built the liberal democratic order seems intent on dismantling it. 

Thomas Kleine-Brockhoff, who oversees the German Marshall Fund’s office in Berlin, said that up until recently, it was popular for defenders of close American ties to console themselves with the mantra “watch what they do, not what they say.” 

But that was before Trump canceled U.S. participation in the Iran deal, threatened European businesses with sanctions and launched steel and aluminum tariffs that could hit Europe as soon as next month. 

“Now the actions are piling up,” he said. “You keep thinking it doesn’t get any worse. But boy, we’re being educated.” 

Kleine-Brockhoff, a former presidential adviser, still counts himself among the defenders of the transatlantic bond. But he said he — and Europe — will have to seriously reevaluate if Trump wins reelection. 

Others in Europe aren’t waiting that long.

“The mood in the country is that we can’t let the U.S. run the world, especially if it’s run by someone like Trump,” said François Heisbourg, a former French presidential adviser on national security and defense. “When an ally treats its allies like enemies, you have a problem.”

Heisbourg said the current strain on the transatlantic relationship is greater than in previous periods of tension.

In the 1990s, there were disagreements over the U.S. and NATO bombardment of Kosovo. Western Europe bitterly opposed President George W. Bush’s war in Iraq in 2003. Even under President Barack Obama — who was extremely popular in Europe — European policymakers first complained about being ignored, then smarted when then-Secretary of Defense Robert Gates slammed them in 2011 for not taking their own defense seriously enough.

But in part because of that evolving estrangement, Trump’s actions look all the more concerning.

“There are trends underway that began before Trump and will continue after Trump,” said Tomas Valasek, the head of the Carnegie Europe think tank and a former Slovak ambassador to NATO. Trump “believes this is a dog-eat-dog kind of world in which one country’s gain is another’s loss. And that applies to the allies as much to the Chinas and Russias of the world.”

For all the transatlantic tiffs in the first year of the Trump administration, the U.S. pullout from the Iran nuclear agreement and the tariff threats have the potential to be far more explosive, because they could lead to Europe and Washington actively trying to undermine each other. 

In Brussels, some are trying to reframe the strained relations as an opportunity.

“We’re not going to live in a world of U.S. hegemony that we can all hide behind,” said Nathalie Tocci, director of the Rome-based Italian International Affairs Institute and a top adviser to E.U. diplomat-in-chief Federica Mogherini.

“We love the United States,” she said. “But when the United States takes a decision that is contrary to our interests, then we should be able to do our own thing and pursue our own policies. The relationship of dependence has to change.”

Still, there are skeptics of Europe’s ability to split from the United States. Europe remains deeply dependent on the U.S. security umbrella, with Germany’s military so rusty that its helicopter pilots are losing their certifications because they don’t have enough working aircraft to practice. 

And despite Trump’s angry rhetoric that Europeans aren’t doing enough to defend themselves, he has poured money into U.S. military involvement on the continent, unveiling a budget proposal this year that would build on a previous increase to nearly double spending compared with Obama’s final year in office.

“Europeans are going to be unwilling to push things to a crisis point with Washington or to pick very serious fights,” said Adam Thomson, director of the European Leadership Network, a London-based think tank, and a former senior British diplomat. 

But there are steps Europe can take. Thomson recently co-wrote a paper calling for Europe’s militaries to make themselves better able to operate independently from the United States — not out of spite, but because improved European defenses would serve both sides.

Jörg Lau, foreign editor of the German newspaper Die Zeit, said such steps are long overdue, and need to take account that the United States isn’t coming back as the steadfast protector it once appeared to be.

Whether it’s Trump in office or any other American president, he said, “U.S. priorities have changed, and why shouldn’t they? It’s not something we should complain about. It’s a fact we have to acknowledge.”

Europe is peaceful, it’s wealthy, and it’s time, he said, for the continent to take care of its own security.

“We can almost be thankful to Trump,” Lau said. “He’s made it clear to Europe that we need to wake up.”

Birnbaum reported from Brussels. James McAuley contributed to this report from Paris.