Timothy Garton Ash, a contributing writer to Opinion, is a senior fellow at the Hoover Institution at Stanford University and professor of European studies at Oxford University. He is the author, most recently, of "Facts are Subversive: Political Writing from a Decade Without a Name."

In the same week it is revealed to us who will be the next leaders of both superpowers: Barack Obama and Xi Jinping. The only difference is that we didn't know it would be Obama until after Tuesday's vote. By contrast, we knew it would be Xi long before the process that begins in the Great Hall of the People in Beijing on Nov. 8, from which he will emerge as Communist Party leader, becoming president next spring.

The coincidence prompts two questions: Which superpower is getting stronger? And which faces the deeper crisis of its economic and political system? Though this may sound contradictory, the answers are: China and China....

..[China] has the more profound systemic problems that, if not addressed, may both slow its rise and make it an unstable, unpredictable and even aggressive state. Over the last five years, the United States has gone through a great time of troubles. I predict that China will face its own time of troubles over the next five....