High-stakes choices for China's leaders It is probably a coincidence that China will parade its new leaders only a couple of days after the US chooses between Barack Obama and Mitt Romney. Mid-October had seemed a more likely date for the 18th congress of the Communist party of China. But there was a line to be drawn under the disgraced Bo Xilai. Then there was the mysterious disappearance of Xi Jinping, the presidential heir apparent. Coincidence or otherwise, the timing is a reminder that the relationship between the two powers will shape the international order for the next several decades. Whether or not the US and China manage to rub along together could make the difference, quite literally, between war and peace. Will they be rivals or enemies? The historical precedents for encounters between established and rising powers are discouraging. Whenever I talk to western officials with long experience of China, I am reminded of just how little is known about its inner workings. China has opened its economy to the world but the personalities and dynamics of its politics remain opaque. As for Mr Xi, his quite numerous encounters with foreigners have thus far presented a perfect definition of inscrutability. Those few who have spent many hours in discussions with Hu Jintao's successor confess to having only the sketchiest notion of where he wants to lead China. He is confident, yes. He thinks that the so-called princelings - scion of the party's revolutionary heroes - deserve their special place in ruling the country. He is animated when the conversation turns to sport. He is better connected in the People's Liberation Army than Mr Hu. That's about it. As for his temporary absence, all the resources represented by the west's diplomats, spooks and eavesdroppers have turned up, well, some plausible speculation. The official story about back strain seems weak. The best alternative guess is that he had some sort of surgical procedure - not life-threatening but sufficient to keep him out of action and out of the public eye for a few weeks. Ask the Sinologists where Mr Xi would like China to be when he steps down in 2023 and conjecture turns to complete guesswork. The fact of China's rise has made his generation more confident than their predecessors. But will confidence turn to arrogance, assertiveness to expansionism? In Washington officials talk about three strands in China's foreign policy. The first of these - Deng Xiaoping's admonition that China should bide its time - forged a masterly compromise between doves and hawks. The former were assured that foreign entanglements would not get in the way of domestic development; the latter that their moment would come when China was sufficiently strong. Mr Deng's wisdom still has a following. A second strand says that even a powerful China has little to gain from conflict with the US: that mutual dependence is a fact of political as well as economic life. Support for this stance has weakened. The third contends that China has suffered enough indignities; the time has come for it to reclaim its rightful status and place in world affairs. The view finds champions in the PLA. Where Mr Xi sits will be critically important. His few public utterances put him closest to the hawkish end of the spectrum. Nationalism runs in the party's bloodstream so he will be no soft touch when it comes to territorial disputes in the South and East China seas. Yet whether this amounts to a desire for confrontation with the US is an open question. Chinese officials have made much of America's economic troubles in the wake of the financial crash. Some see the start of an inexorable decline. Others are less sure. The US has many advantages, from demography to economic dynamism, geography to technological prowess. Either way, Mr Xi will inherit his own challenges. The defenestration of Mr Bo may have settled the power struggle at the top but China can no longer rely on double-digit economic growth. The population is ageing. Wages are rising and workers are no longer pliant - witness the recent rioting at plants run by the Foxconn contract manufacturer. There is no great clamour for western-style democracy, but China's digital media buzzes with calls for more accountable governance and for an end to the corruption that fuels the ostentatious consumption of the super rich. Mr Xi's first, second and third priority will be to sustain party authority in the face of this rapid and unpredictable social upheaval. There are two sides to any relationship. If it is fair to say a more assertive China signals dangers ahead, will the US do anything to steer Beijing away from a zero-sum approach to great power politics? The rhetoric of the presidential campaign scarcely lifts the spirits. Mr Obama promises to restrict Chinese imports; Mr Romney wants to declare Beijing a currency manipulator. Paul Ryan, the Republican vice-presidential contender, thinks it is time for the US to "go to the mat" with China, whatever that means. Mr Obama's "pivot" to Asia has prompted a counter-reaction in Beijing. Yet China is by no means entirely at fault in the latest maritime flare-ups. The return of the US has emboldened some of China's neighbours. Beijing sometimes has a case when it says that others were first to disturb the status quo. There are no quick fixes to these disputes, rooted as they are in both history and access to future natural resources. What is needed is a new status quo to avoid the ratchet effect. An east Asian arms race is in no one's interest. And there is a lot more at stake than a string of uninhabited islands.