In what was supposed to be a warm reunion, US Vice President Joe Biden and Chinese President Xi Jinping meet instead today in a climate fraught with tension over an airspace dispute that has put Asia on edge.
A day before seeing Xi, Biden stood in Japan and publicly rebuked China for trying to enforce its will on its neighbours, escalating the risk of a potentially dangerous accident.
Although Biden had hoped to focus on areas of cooperation as the US seeks an expanded Asia footprint, China's declaration of a new air defence zone above disputed islands in the East China Sea has pitted the US and China against each other, creating a wide gulf that Biden will seek to bridge during his two-day trip to Beijing.
Stepping off his plane in Beijing in his signature aviator sunglasses, Biden was met by a Chinese military honour guard before being whisked to the US Embassy, where the vice president was visiting the consular section to highlight efforts to reduce visa processing times for Chinese visitors to the US.
After an official welcome ceremony later at the Great Hall of the People, Biden was to meet with Vice President Li Yuanchao before his evening session with Xi.
Despite Washington's preference not to get involved in a territorial spat, concerns that China's action could portend a broader effort to assert its dominance in the region has drawn in the US, putting Biden in the middle as he jets from Japan to China to South Korea on a weeklong tour of Asia.
''We, the United States, are deeply concerned by the attempt to unilaterally change the status quo in the East China Sea,'' Biden said after meeting in Tokyo on Tuesday with Japanese Prime Minister Shinzo Abe.
''This action has raised regional tensions and increased the risk of accidents and miscalculation.''
To that end, Biden said he would raise those concerns with China's leaders ''with great specificity'' during his Beijing visit.
As if to make a point that the newly declared air defence zone would be a major topic of Biden's talks with the Chinese, China's Defense Ministry issued a statement reiterating the country's determination to enforce the zone just as the vice president was arriving in Beijing on Wednesday.
China's military is ''fully capable of exercising effective control'' over the area covering the disputed islands in the East China Sea, said ministry spokesman Geng Yansheng.
Although the US has repeatedly said it rejects the zone, Biden has avoided calling publicly for Beijing to retract it, wary of making demands that China is likely to snub.
Rather, the US hopes that with enough pressure, China will refrain from strictly enforcing the zone, essentially nullifying it for practical purposes.
What's more, the US wants to show that the diplomatic consequences for such actions are severe enough that China will think twice in the future about asserting its authority in such heavy-handed ways.
Already, China has claimed it has a sovereign right to establish a similar zone over the South China Sea, where China and the Philippines are locked in another long-running territorial dispute.
The East China Sea zone covers more than 1000km from north to south above international waters separating China, South Korea, Japan and Taiwan. China says all aircraft entering the zone must notify Chinese authorities beforehand or face unspecified defensive measures.
The new round of tensions with China comes as the US is striving to increase its own engagement, influence and military presence in Asia, in part as a hedge against China's growing power. But the Obama administration has said it's pursuing a new model for engagement with China, where the two countries can cooperate economically while maintaining a healthy competition.
''There is a mistrust here by China of US intentions,'' Senator Ben Cardin, who chairs the Senate's Asia panel, said.
''China is not clear why the US is interested in Asia. They think it may be to affect China's development in a negative way - and nothing could be further from the truth.''
It wasn't always this way.
When Biden came to China two years ago, Xi brought him far away from Beijing's congested streets and sober government buildings to Chengdu, an ancient city in lush southwestern China.
At the end of a long day of touring, the two set off for a stroll to view an irrigation site built by the Qin Dynasty in 256BC and still used today.
Walking with Biden along an ornately painted walkway overlooking the canal below, Xi had ditched his jacket - a rare departure from the stiff formality traditional of Chinese officials.
Aides travelling with Biden said it was moments like these that offered some of the first clues that Xi, now China's president, might be different.
During hours spent with Biden on the road, Xi began to reveal a bit about his personal style, giving the American delegation a glimpse into how he might one day rule the world's second-largest economy.
Knowing Xi was poised to eventually become president, the White House had turned to Biden to feel him out during a pair of official visits while Xi was still vice president.
The goal was to make an early down payment on a relationship that would surely be critical as China gained political and economic clout on the world stage.
''If you look at Xi Jinping's personality, he seems to really demonstrate some aspects of Chinese traditional culture. You give high regard to personal trust,'' said Li Mingjiang, a China expert at Singapore's Nanyang Technological University.
''Not a formal or legal commitment per se, but in Chinese culture, a lot of things can be done simply on trust.''
Whether that trust can serve as a basis for Biden and Xi to de-escalate tensions during Biden's stop in Beijing remains to be seen.
Unlike Biden's last trip to China, this visit will have few of the casual moments or long get-to-know-you sessions that also characterised Xi's 2012 visit to the US, where he visited small-town Muscatine, Iowa, and spent hours with Biden in Los Angeles.
Before departing China on Thursday, Biden will have breakfast with American business leaders and meet with China's premier, Li Keqiang. The vice president will then fly to Seoul, South Korea, for the final leg of his trip.