BRUSSELS – Many European leaders have been treated with contempt by President Trump, who sees them as competitors and losers rather than allies, and eyeing the possibility of a Biden presidency. But they are painfully aware that four years of Mr. Trump’s existence have changed the world – and the United States – in ways that will not be so easily reversed.

Even if civility can be restored, basic trust has been broken, and many European diplomats and experts believe that the foreign policy of the United States is no longer bipartisan and thus no longer reliable. “The bright city on the hill is not as bright as it used to be,” Reinhard Boutecover, the leading German member of the European Parliament, said bluntly.

“Europeans fear that there is no consensus on foreign policy in the United States,” Evan Krastev, director of the Center for Liberal Strategies, said for the first time. Every new administration could mean a completely new policy, and that’s a nightmare for them.

The ideological split will be shown on Thursday, when Mr. Trump and Joseph R. Biden Jr. The final presidential debate is scheduled to take place.

There will be what most people see as the hanging fruits of the Biden administration that will please Europeans. The crop includes an extension of the New Beginning Treaty to limit nuclear weapons with Russia, and goes back to the Paris Climate Agreement, the World Health Organization and even the Iran nuclear deal. There will be satisfying meetings and statements of multilateralism, there will be less confrontation over trade, renewed efforts to reform the World Trade Organization, and a less bellicose atmosphere at the G7 and NATO summits.

But many Americans share Mr. Trump’s grievances, and given the polarization in America, French President Emmanuel Macron has pushed Europe to advance in a changing world, where China is rising and the Trump administration is only a symptom of American retreat. From global leadership, not the case.

The idea of ​​”European strategic independence” – for Europe less dependent on Washington and its strong voice in the world – is gaining ground, even if it is more ambitious than real.

Some, like Natalie Tucci, director of the Italian Institute of International Affairs, and Francois Heisburg, a French security analyst, fear that Biden’s presidency will shorten the European autonomy and allow the Europeans to continue, says Ms Tucci, Raml.

Trump’s re-election, of course, may accelerate the trend toward autonomy, even if few believe that Mr. Trump will be able to withdraw from NATO, as one of his former national security advisers, John Bolton, Maybe he suggested.

US foreign policy has traditionally been bipartisan – the old phrase that “politics stops at the water’s edge” has an advantage, especially during the Cold War. But the collapse of the Soviet Union meant that foreign policy, too, was vulnerable to deepening political polarization in the United States.

“There is an unbelievable degeneration in Europe of the United States’ feeling as a leader, ”as it accelerates and codifies it By mishandling the CoronavirusSaid Jeremy Shapiro of the European Council on Foreign Relations.

He said, “Biden does not solve their American problem.” “He will not be president forever, and the Democrats will not always be in power. People have learned that the United States cannot be trusted in foreign policy, because the next administration will come and wipe it out.”

Some have warned that the inconsistency in US foreign policy has undermined American credibility.

“There is an American decline in geopolitical weight,” said Francis Fukuyama of Stanford University. He said, “The only fact that shapes the US role in world politics is polarization, and this polarization will not disappear if Joe Biden is elected.” “Americans simply do not agree with each other on the basic premises, even on the extent to which America is involved in world affairs and NATO.”

William J. Burns, a former senior American diplomat who now runs the Carnegie Institution in Washington, says the damage is permanent, regardless of who wins the election.

“One of the most pernicious effects of polarization is making foreign policy a tool for partisan politics,” he said. “It has caused permanent damage to America’s reputation in the world for its ability to fulfill its promise.”

While Europeans will see Biden’s presidency as a “return to civilization,” as Mr. Heisburg called it, the new partnership will come with demands for new commitments and pledges, especially with regard to China.

Mark Leonard, director of the European Council on Foreign Relations, said that after Mr Trump, there will also be new caution and an unwillingness to take great risks on the part of America’s allies. He said, “If you know that everything you do will continue in the end until the next election, then you look at everything in a much more probable way.”

Europeans see the US confrontation with China as one of the few bipartisan issues driving US foreign policy, and Europeans are reluctant to become a pawn or playing card in this rivalry, given that China is Europe’s second largest trading partner after the United States. States.

Polls Turns out Most Europeans do not want to take part in some of the battles between Washington and Beijing. “We don’t see China challenging the same way, and we are not a peer competitor,” said Rem Cortiwig of the Clingendael Institute.

There will also be continued pressure from Washington on Europeans to spend more on defense – a bipartisan demand that has not been dismantled.

Mr. Trump has succeeded in getting the Europeans to spend more. But the Europeans were also reacting to the transatlantic leadership vacuum, doubts about Mr Trump’s commitment to collective security and his view of Europe as a A burden and a competitor.

“I see European partners are more assertive in saying that we disagree with US policies – this is the healthiest legacy that Trump has left,” said Alexandra de Hoop Scheffer, director of the German Marshall Fund in Paris.

Before Trump, those disagreements were hardly material.

“We had disagreements, but there was never a fundamental mistrust about having common views about the world,” said Gro Harlem Brundtland, a former Norwegian prime minister who has dealt with many American presidents of both parties.

But over the past four years, she said, “many European leaders no longer take for granted that they can trust the United States, even on basic matters, for granted.”

She said confidence in Washington will not return quickly. “While most European leaders think it is better for the world order to build on a close relationship between the United States and Europe, such a polarized position between the two major parties in the United States is frightening,” she said. “You wonder where this is going.”

For Mr. Burns of the Carnegie Endowment, America’s global dominance is over. He sees little American desire for “the Great Crusades in foreign policy” and says, “We can’t go back to 1949 or 1992 – or even 2016. The world has changed, and the transatlantic relationship with it must change.”

He said the Biden administration would focus first on domestic regeneration in a country hit by the coronavirus. He will seek a more cooperative partnership with Europe, and support “a European security identity that does not come at the expense of NATO.”

Mr. Burns said that Europeans have “their own doubts, given the drift they have seen in America that is moving more inwardly.” But practical alliances are possible in China, 5G, Russia, Africa and climate change.

Mr Burns said the Europeans should also commit. “Both sides should intensify investment in a new relationship, which they did not always do in the past.”