More upside: great food, great people, great time. I'd recommend taking one pilgrimage to China, if only to confirm that it's there — so very there, so very much of it; these vast overnight metropolises are physically improbable. Moreover, after one visit to Beijing you know their government can't possibly control this many people and keep tabs on what they think. For a nominal fee, a virtual private network will elude the censors, and I spent a pleasant morning reading nytimes.com in the Bookworm café, though the website was officially blocked.

The fact that all over Beijing you have to put soiled loo roll in a little basket beside the toilet is telling: the infrastructure is fragile. It's easy to imagine that finally one too many migrants arrives, and all those tower blocks collapse like dominoes. The plain practical challenge of keeping Beijing and countless cities of similar size from imploding or coming to a standstill surely absorbs the majority of the regime's energies. I left China horrified and awed in equal measure. I'm betting the party's functionaries are less concerned with blocked websites than blocked toilets.