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.