The first two walls (by which I mean the Great Wall and the Great Firewall, of course) have their ugly moments: the swarming hawkers, the inexplicable and annoying censorship of Eyes East… But in the end it’s all just kind of quaint. Wink wink, nod nod. We all know those walls are full of holes — a pretense kept up for showing the mandarins that the bureaucrats are working hard to preserve harmony.

But the third wall is stone-faced and blustering, maybe even frightening. Few foreigners outside (mainland) China have seen it, but no foreigner in China for any amount of time could have missed it. Usually if you visit once, you don’t go back. It starts off as an innocent enough conversation. You think you’re exchanging honest opinions about the nature of governance. Then all of a sudden the tone is truculent — livid if you decide to push. You’re getting a lecture about foreign powers trying to divide and conquer China and how you’ve been brainwashed by the foreign media and couldn’t possibly understand anyway.

Maybe that’s all to be expected. Jingoism in any country is distasteful, and every country has it. But the “maybe frightening” part is how few chinks there are in this wall. As you first approach the wall, you might laugh it off, knowing off the top of your head half a dozen independent-minded friends who’d be happy to let you past. It’s only when you get there that you realize your mistake. They’re not just not letting you through, they are enthusiastic enforcers of the wall’s integrity. There is only one China, they are sure, and you wonder what means they’ll go to to enforce that belief.

Yikes. And don’t even think about bringing up the other T word from the west.