GENEVA - Standing under the wing of Air Force One in Geneva on Wednesday - after a week-long trip abroad in which he repeatedly extolled the virtues of democracy over autocracy - President Joe Biden seemed briefly to knock his own product.

"I never anticipated - notwithstanding, no matter how persuasive President Trump was - that we'd have people attacking and breaking down the doors of the United States Capitol," Biden said, referring to the Jan. 6 siege. "I didn't think that would happen, I didn't think I'd see that in my lifetime."

But then, like any good pitchman, Biden quickly regained his footing. He said the mob attack had simply reaffirmed what he'd long been taught, by everyone from his political science professors to his former Senate colleagues: "Every generation has to reestablish the basis of its fight for democracy. I mean, for real, literally, have to do it."

As Biden hopscotched across Europe this past week on his first trip abroad, his most prominent message, repeated everywhere, was the need for democracy to prevail over autocracy in what he cast as the existential challenge of the 21st century. America, he promised, was back at the helm of that struggle.

But the fight for democracy, or a version of it, is unfolding not just in Europe but also in the United States, and Biden's message is complicated by the turmoil in the country he leads - the Jan. 6 attack, Trump's claim that the 2020 election was stolen, the push to restrict voting, the ongoing "audits" of elections whose results have long been settled.

In fighting for democratic values abroad, Biden risks seeming as though he is looking past the threats in his own country.

"Anytime you have a really divided country, it's going to make the president look weaker," said Michael Kazin, a Georgetown University historian. What is especially striking now, he added, is how many Americans question Biden's victory and say they are open to political violence: "A disputed election is one thing. It's another thing to have a large number of people in the losing party say that they don't accept the results."

Biden visibly wrestled with this challenge at times during his week-long trip to Cornwall, Brussels and Geneva. At NATO headquarters in Brussels, he paused and let out a small sigh before answering a question about how the assault on the Capitol, and America's polarized politics in general, might undercut his credibility with allies who know that Trump or a Trump-like figure could be back in power in Washington in a matter of years.

He essentially argued that Trump was an aberration. "I'm not making any promises to anyone that I don't believe are overwhelmingly likely to be kept," Biden said. European leaders, he added, "know our recent history - know, generically, the character of the American people" and believe, as he does, that "the American people are not going to sustain that kind of behavior."

The dilemma is unlikely to fade anytime soon. Biden's next foreign trip could come this fall, when the Group of 20 meets in Rome and a climate summit is held in Glasgow. At the same time, Trump has signaled that he will ramp up his activities, holding rallies and endorsing candidates as he continues to promote the claim that the election was stolen, with many Republicans vocally agreeing.

And Biden also faces doubts from more liberal quarters.

Rep. Pramila Jayapal, D-Wash., the chair of the Congressional Progressive Caucus, said democracy is in serious peril in the United States. Nevertheless, she said, that shouldn't stop Biden from promoting democracy over autocracy on a global scale.

"There's no question we have a lot of work to do to protect our democracy here, and I think we saw on January 6 how close we came to losing it," Jayapal said. "But I don't think that undermines our ability to make that argument around the world. I actually think in some ways it strengthens our argument to say, 'We are dealing with these same factors in the United States.' "

Yet in making his pitch on his first trip abroad, Biden largely steered clear of underscoring the problems in the United States, as Jayapal suggested.

"The truth is that we still do have a democracy. And it's teetering. It's on the brink," Jayapal said. "If we don't pass these voting rights laws, then I think we will be in a position where people will no longer look to America, and we've already seen that happen in some ways."

Biden's position in some ways echoes that of American leaders in the aftermath of World War II, when the United States faced off against the Soviet Union for the moral high ground. America's case at the time was damaged by racism and segregation at home, which Russian leaders were quick to highlight.

As Biden made his way across Europe this past week, he hugged democratic allies close after the estrangement and hurt feelings of the Trump years. He also tried to put some victories in democracy's column at every stop.

He succeeded, but only to a point that illustrated the limits of democratic consensus.

In Britain, for example, Group of Seven leaders announced that rich democracies would give one billion coronavirus vaccines to poorer nations, but that came only after months of complaints that the United States, Canada and other wealthy nations were hoarding vaccines, a phenomenon critics called "vaccine apartheid."

And the donation, while large, was immediately branded insufficient to meet the needs of vaccinating the world population. "We need more than that," U.N. Secretary General António Guterres said, even as he welcomed the effort.

The United States is contributing half the total - 500 million Pfizer-BioNTech vaccines - in what Biden framed as the U.S. reclaiming leadership at a moment of crisis. "America will be the arsenal of vaccines in our fight against covid-19, just as America was the arsenal of democracy during World War II," he declared.

Biden also prodded allies to adopt a newly skeptical view of China, but neither the G-7 nor NATO went as far as he had hoped in naming and shaming what the United States calls exploitative Chinese investments and aggressive Chinese military posturing.

A surprise announcement in Brussels that the United States and Europe had resolved a 17-year trade dispute over aircraft manufacturing was framed as a unified answer to competition from Chinese-made wide-bodied planes. But the marquee deal is essentially a punt that delays for five years the hardest questions about government subsidies.

That means the Boeing vs. Airbus trade saga, and the union labor fires it stoked in the United States, are on a back burner until after the next presidential election.

The summer camp vibe of democratic good feeling became a solo journey when Biden arrived in Geneva for a summit with Russian President Vladimir Putin, which in some ways came down to a mano-a-mano dispute over democracy in the United States.

After a three-hour meeting at a historic villa in Geneva, Putin seized on Biden's tumultuous domestic situation to dismiss human rights abuses in his own country. He portrayed the attack on the Capitol as laudable and racial justice protests as anti-democratic, echoing the perspective of many on the right.

Pressed on why so many of his political opponents wind up poisoned, jailed or dead, Putin accused the United States of killing and imprisoning peaceful political protesters involved in the Jan. 6 riot. The veteran Russian leader, who has consolidated power and wealth while neutering political opposition, went on to say that his crackdown on opposition leaders is partly to avoid the rise in Russia of movements like Black Lives Matter.

Ian Bremmer, president of the Eurasia Group, a risk assessment firm, said Putin was essentially deploying what partisans in the United States have taken to calling "whataboutism," citing an opponent's alleged faults to distract from one's own.

"It is certainly true that the United States needs to build its credibility domestically if it wants to be the moral leader of democracy abroad," Bremmer said. But, he added, "Let's not pretend there is a moral equivalency, which is what the Chinese and Russians are trying to claim."

"As bad as it has been in the United States, and it has been bad in the United States - a lot of Republicans don't believe in representative democracy at this point - the United States remains not remotely comparable to Russia as a system or China as a system," Bremmer said.

In his own news conference after Putin's, Biden dismissed the Russian leader's equation of Russian pro-democracy protesters with Americans who stormed the Capitol to overturn an election, calling it "a ridiculous comparison."

Behind Biden's derision lay broader questions about the durability of slow, messy, elected governance in the face of speedy if imperfect solutions offered by China, Russia and other autocratic powers. The G-7 vaccination announcement was in part an effort to respond to such questions.

Biden himself alluded to the quandary at his first stop in Europe, a slickly produced, Stars-and-Stripes extravaganza at a British military base that houses an American air wing.

"How we act, and whether we pull together as democracies, is going to determine whether our grandkids look back 15 years from now and say, 'Did they step up? Are democracies as relevant and as powerful as they have been?' " Biden said.

It's not a new theme for Biden, whose foreign policy views were formed by the post-World War II vision of an American-led alliance of democracies against communism.

That vision often fell short, as when the United States embraced brutal regimes if they opposed the Soviet Union. Biden, too, has been criticized for being overly tolerant of authoritarians like Egypt's Abdel-Fatah al-Sissi when he needed their help.

Still, promoting democratic values has in some ways become an organizing message for Biden's presidency. "I predict to you, your children or grandchildren are going to be doing their doctoral theses on the issue of who succeeded: autocracy or democracy?" Biden said during his first official news conference in March. "Because that is what is at stake."

A month later, addressing a joint session of Congress in April, Biden again returned to the idea, urging Americans to show the world that democracy is still the best form of government.

"Can our democracy deliver the most - to the most pressing needs of our people? Can our democracy overcome the lies, anger, hate and fears that have pulled us apart?" Biden said. "America's adversaries - the autocrats of the world - are betting we can't."

Upon returning home this week, Biden's team was quick to declare the trip a success - not just for the president, but for democracy writ large.

"The bottom line is that Joe Biden confidently and skillfully donned the mantle of leader of the free world on this trip," national security adviser Jake Sullivan told reporters. "The previous president had ceded that mantle, and this president has now emphatically reclaimed it."

Around the same time, Trump, who continues to claim aggressively that the election was stolen from him, signaled plans for big rallies in coming weeks.

Sullivan reported from Washington.