Washington ? The photograph on Tuesday from Beijing was as carefully arranged as a display of Ming china: Presidents Barack Obama and Xi Jinping discussing the world’s business as they walked, side by side, across a bridge with ornate, brilliantly illuminated guideposts.

The artfully staged image conveyed a message: China has arrived as a great power. Its leader stands nearly as tall as the American president (and he’s ready, as he showed later, to speak American-style, without notes, at a news press conference). Rather than insisting on its inability to share responsibility, a strong China is ready to do business.

The surprise of the Beijing summit was that a weakened President Obama, a week after a pulverizing midterm election, was able to gain significant agreements on reducing climate change, lowering tariffs for information technology, sharing intelligence about counterterrorism and helping the two nations’ militaries avoid miscalculations.

“The summit was more successful than most expected,” says Ken Lieberthal, a leading China analyst at the Brookings Institution. Obama and Xi “took a relationship that was increasingly scratchy and fractious” and showed they could make it work. Kurt Campbell, who was Obama’s assistant secretary of state for Asia and is now a consultant, agrees that Obama “played a weak hand much more effectively than expected.”

Why did this summit deliver results when U.S. diplomacy has been faltering elsewhere? One simple explanation is that the White House worked hard to prepare the ground. National security adviser Susan Rice traveled to Beijing in September for talks. Counselor John Podesta worked nearly a year preparing the climate-change package. David Shear, an assistant secretary of defense, rapidly crafted confidence-building measures to reduce tensions at sea and in the air.

“Chapeau,” says Peter Wittig, German ambassador to Washington, using a European term of congratulation. “I would praise the process, which was professional and discreet. Nothing leaked before the meeting.”

At a deeper level, the Beijing summit symbolized China’s embrace of its new status as a great power — which is a mixed blessing from the U.S. standpoint. In past encounters, Chinese leaders have often responded to U.S. requests for cooperation by insisting on their weakness: China is still a poor country; its military is tiny compared to that of the United States. U.S. officials have come to see this “humble pie” talk as a way of ducking responsibility; China’s strategy, in their view, was to “hide and bide,” until ready to stand level with the U.S.

This moment may have come in Beijing. “China is ready to work with the United States to make efforts in a number of priority areas,” said Xi in his joint news conference with Obama. This appearance was itself a show of confidence (and of intimidation, in Xi’s remarks about journalists).

Obama sounded a similar note of realism about cooperation with the new China: “Even as we compete and disagree in some areas, I believe we can continue to advance the security and prosperity of our people.”

Explains Campell: “What Xi has done is demonstrate that he’s comfortable with China being depicted as a powerful state.” Obama responded by showing that the U.S. is ready to engage this powerful China, as long as it acts responsibly.

Campbell cautions about the complexity of the relationship. In American eyes, most countries are either friends or foes. But the China relationship, argues Campbell, will be a “hybrid model … with areas of brutal competition and areas of necessary cooperation.”

On the path to this summit, Xi demonstrated his power and self-confidence, to a fault. He reached out to Russia, cleverly playing the triangular game of superpower politics; he tried to intimidate Japan and other Asian neighbors with claims of China’s territorial waters; he conducted an anti-corruption purge at home that shook up the party, and tightened its authoritarian screws.

But Lieberthal argues that in recent weeks, Xi sensed it was “time to dial back,” especially toward Japan. Just before the summit, a Chinese statement appeared to ease confrontation on the disputed Senkaku-Diaoyu islands and move the issue to the murky “to be solved later” file, long reserved for Taiwan. This seems to be a victory for Japanese Prime Minister Shinzo Abe, who had hung tough during Chinese threats. Meanwhile, China seems to have backed away slightly from its embrace of the mercurial Russian President Vladimir Putin, whose macho gesture of draping his coat over Xi’s wife at Monday’s dinner seemed more Sancho Panza than Don Quixote.

One U.S. analyst cites a Mao Zedong proverb that’s a caution in assessing the neo-realism of the Beijing summit: “Despise the enemy strategically, but respect him tactically.”