Biden declared that ‘America is Back!’ in June. The World Is About To Test Him.

WASHINGTON — When President Biden gathered with world leaders at an English seaside resort in June, it was a backslapping celebration of America’s return to diplomatic stability after four years of public dressing-downsAnd impulsive policy withdrawalsUnder President Donald J. Trump

“America is back at the table,” Mr. Biden declared at that meeting, the Group of 7 summit.

The president has learned that being Mr. Trump is not enough for him to achieve his goals at home and abroad in the turbulent four months since.

In his final public remarks before he leaves Washington for the Group of 20Mr. Biden failed to unite Democrats behind a $1.85 Trillion economic and environmental spending program, despite his gathering in Rome this weekend. This blueprint contained more than $500 billion to combat global climate change. He hoped to use it as leverage to get commitments from other leaders during his visit to a summit on climate in Scotland early next month.

“It’s about expanding opportunity, not opportunity to deny,” Mr. Biden said on Thursday. “It’s about leading the world. We’re letting the world pass us by.”

Biden, who often refers back to his skills and experience as a negotiator and decades of foreign policy experience, will seek out foreign leaders to make commitments to stop the pandemic and untangle supply chain knots. He also wants to slow down the inflation rate around the world. He will also counter criticisms about the August chaotic withdrawal of American troops Afghanistan and repair the rift with France over a deal for a nuclear submarine.

“I do still think that the president enjoys a tremendous amount of fundamental good will in Europe,” said Ian Lesser, acting president of the German Marshall Fund of the United States. Despite this, recent polling from Gallup shows that America’s standing around the world has rebounded from the lows of the Trump era, “just because Biden is not Trump doesn’t make all of the policy issues easy to address,” Mr. Lesser said.

Biden will visit Pope Francis to begin his time in Rome. Diplomacy is next on the agenda. He will meet Sergio Mattarella, Italy’s president, and Mario Draghi, its prime minister, and hold another meeting later that day with President Emmanuel Macron of France. Giving the French priority is a signal that Mr. Biden is trying to assuage them after the United States reached an agreement to provide Australia with nuclear submarines — effectively cutting France out of its own multibillion-dollar submarine deal with Australia.

The president will not meet with two rival leaders — President Vladimir V. Putin of Russia and President Xi Jinping of China — who are staying home from the conference over Covid concerns.

Before the trip, Jake Sullivan, the president’s national security adviser, discounted the idea that Mr. Biden would have less of a leadership role at the two summits if he traveled to Europe without a signed economic and environmental spending deal, or the passage of the major infrastructure bill pending in Congress.

Speaking with reporters on Thursday aboard Air Force One en route to Rome, Mr. Sullivan said Mr. Biden would announce plans to modernize stockpiles and “create resilient supply chains.” He said another major focus at the G20 would be securing a communiqué that would outline a plan to protect the globe against future pandemics.

“What the G20 will be focused on is the future,” Mr. Sullivan said. “How do we prevent a future pandemic? How do we ensure that the world is coordinated in a way that it wasn’t sufficiently coordinated when Covid-19 hit last year?”

And Mr. Sullivan stated that the president did not see the absence of Mr. Putin or Mr. Xi as a problem to coordination, but rather as an opportunity to show that Western democracies can work together to address current and future threats. On Saturday, Mr. Biden’s first major meeting of the summit will be focused on economic policy and the pandemic, and then he will meet with the leaders of France, Germany and Britain to discuss ways to get the 2015 nuclear accord with Iran back on track, one of Mr. Biden’s most elusive diplomatic goals since assuming the presidency.

Gita Gopinath, the chief economist at the International Monetary Fund, said that the most urgent economic task for leaders at the G20 summit is slowing the pandemic — in large part, she said, by making good on promises to ship vaccine doses to less wealthy nations that remain critical to supply chains and the global economy but have struggled to gain access to shots.

“To truly end this health crisis and its accompanying economic crisis, we need to get to widespread vaccinations everywhere in the world,” Ms. Gopinath said.

Mr. Biden’s advisers said he was counting on at least one economic policy victory from the conference: the blessing of a global agreement to set minimum levels of corporate taxationThis law was created to stop companies from hiding income in tax havens such as Bermuda.

Mr. Biden’s softer diplomacy skills will be put to the test when he meets with Mr. Macron hours after he arrives in Rome. In September, Mr. Biden’s administration caused a diplomatic rowAfter failing to notify the French of its agreement to sell nuclear-powered submarines in Australia, which was a breach of a $66 billion French project to construct attack submarines, Australia reached an agreement with them.

The deal, announced as part of a new defense alliance with Britain and Australia, so infuriated the French that Mr. Macron recalled his country’s ambassador to the United States, Philippe Étienne, for several days. American officials, including Antony J. BlinkenThe secretary of state and several other officials have rushed through France to try to repair the damage. In November, Kamala Harris, the vice president of the United States, will be in Paris.

Célia Belin, a visiting fellow in the Center on the United States and Europe at the Brookings Institution, said in an interview that the Biden administration seemed to forget “the tasteful art of diplomacy.”

Since the crisis, Macron has openly spoken out about the need for European countries to practice strategic autonomy. This policy would eventually mean that countries like France would be less dependent on the United States for military aid. Europeans will be closely watching the summit to see whether Mr. Biden supports it, Ms. Belin said.

Biden is expected to address at the very least one more diplomatic problem while abroad. Turkey’s President Recep Tayyip Erdogan has been a prominent figure in recent days. has threatened to recall its ambassador to the United States after several embassies, including America’s, called for the release of an imprisoned activist.

The national security adviser, Mr. Sullivan, stated that he expected Mr. Biden to meet Mr. Erdogan in Scotland.