Sitting next to Xi Jinping during one of their marathon sessions in 2011, Joe Biden saluted the direction of US-China ties.
"The trajectory of the relationship is nothing but positive," Biden told businesspeople who came to see the two vice presidents at a Beijing hotel, voicing "great optimism about the next 30 years".
As the two leaders, now presidents, prepare to meet again little more than a decade into that timeframe, the trajectory of relations is anything but positive -- and virtually no US policymaker is optimistic about Xi, China's most powerful leader in decades who just secured a historic third term.
Biden and Xi will hold talks Monday on the sidelines of a Group of 20 summit in Bali at a time of rising US alarm. Xi's China, in the words of Secretary of State Antony Blinken, has become "more repressive at home" and "more aggressive abroad" -- with the threat of China invading Taiwan, once largely theoretical, increasingly seen as real.
It will be the first in-person meeting between the US and Chinese presidents since Donald Trump spoke in 2019 with Xi, who only recently resumed international travel following the pandemic.
But Biden and Xi know each other unusually well for two world leaders. They have talked by phone or videoconference five times since the Democrat entered the White House in 2021.
And the relationship goes much deeper.
When Xi was leader in waiting, Biden flew to China in 2011 and later invited him to tour the United States including rural Iowa, where a young Xi had gone on an exchange.
Biden said that as vice president he spent 67 hours in person with Xi, part of an effort by the then administration of Barack Obama at least to understand, if not court, the rising Chinese leader.
- Cold calculations -
US officials and experts have since come to believe that the 69-year-old Xi has no desire for moderation, with the new Central Committee of the Chinese Communist Party stacked with hardliners and lacking any obvious heir apparent.
"We all knew that Xi Jinping was going to prevail. But I think people are still surprised that Xi Jinping could not even find the grace to save some accommodation for his political opponents," said Yun Sun, a senior fellow at the Stimson Center in Washington.
With the Party Congress over, Xi now has greater space and flexibility to focus on his international push for a stronger China, she said.
"We are not looking at a Xi Jinping who is going to be less emboldened,” she said.
Both Biden and Trump have identified China as the preeminent global competitor to the United States. But while Trump by late in his term was railing against China on everything from trade to Covid-19, Biden has supported talks on narrow areas of cooperation.
Biden told reporters Wednesday he would speak to Xi about each country's "red lines" in hopes of avoiding conflict.
Chief among red lines for China is Taiwan, the self-governing democracy Beijing claims as its own, with Beijing carrying out exercises seen as a trial run for an invasion to protest against House Speaker Nancy Pelosi's visit in August.
Biden has said three times that the United States would defend Taiwan militarily if China attacks, although the White House has walked back the apparent shift from longstanding US ambiguity.
Privately some US allies have cheered on the more forceful approach towards Beijing including on the South China Sea, where Washington has moved from neutrality to championing Southeast Asian nations' myriad claims.
"There is a widespread feeling that the United States has finally understood the nature of the threat," said a senior Washington-based diplomat from an Asian country friendly with the United States.
- Inching away -
The United States has also made initial moves with allies on a once unthinkable idea -- easing two decades of economic reliance on China, which is racing ahead under Xi to dominate next-generation technology and where Covid lockdowns have exposed the fragility of supply chains.
"Seeing what the US is doing to sort of de facto decouple or separate, at least in the technology space, that may be changing calculations" of other Asian countries, said Matt Goodman, senior vice president for economics at the Center for Strategic and International Studies.
Biden has voiced hope for working with China, the largest carbon emitter, on climate change, and officials said Saturday that Biden would press Xi on North Korea, a Chinese ally that has launched a volley of missiles in recent weeks.
Yun doubted China would oblige, saying that Xi views cooperation as transactional.
"With competition the main theme of the US's China policy, why would China cooperate?" she said.
"Their calculation is that they are not going to do anything from the goodness of their hearts. They want to see the US give something."