So an artist of debatable merit (if unquestionably a man of talent) has been imprisoned by a nervous regime on dubious charges, and is championed by Westerners with dubious records on China. But then it is futile to insist on facts, the media being very much the message in such cases. What matters now is whether the Communist Party has the sense to resolve the Ai Weiwei affair swiftly, perhaps by imposing some heavy fines, or contrives in its stubbornness and paranoia to go on building him into a cause célèbre, in a way that could signal a new phase of the protest movement in China, and force Western governments to ratchet up their protests, with all that could mean for their economic interests.

That sounds ominous, yet from another perspective the Ai Weiwei episode could be a cause for hope. Are China's increasingly vicious measures against reformers self-defeating? Are their Canute-like efforts to stem the internet tide destined to fail, as word of Ai's arrest and that of others spreads beyond the intellectuals into the middle classes, and becomes a focus for their discontents? Is this just the beginning? Could it all end like Soviet Russia?

In Beijing's repressive methods there are surface similarities with Moscow. As in Soviet times Chinese dissidents, whistleblowers and petitioners are being sectioned as mentally ill and consigned to psychiatric wards. Imperviousness to world opinion where the legitimacy of the regime was concerned was a feature of Soviet repression too: the award of the Nobel Peace Prize to the internationally acclaimed scientist Andrei Sakharov in 1975 did not prevent his arrest and exile five years later, any more than it has protected Liu Xiaobo. Then, in 1989, under Gorbachev, Sakharov was elected to the new Soviet Parliament.

It is easy to become lost in such comparisons, and a mistake to be too sanguine about the role of China's dissidents in the future. Some basics. The Soviet Union did not collapse because of constraints on intellectual freedom, but because compared to the West it was in a state of all-round decline. In post-Mao China life for the majority has become immeasurably better: when your leaders stop purging or starving you to death by the million, that in itself is progress, not to speak of the country's extraordinary economic advance.

My first sight of China was in 1966 during the Cultural Revolution; my most recent, last year, with many a visit in between. It is a different country, and not just materially speaking. We will get nowhere in our musings about human rights in China unless we recognise that for all the current backlash the country remains infinitely freer than at any time since the 1949 communist revolution. The Chinese security people may appear to be winning out at the moment, but as Ai Weiwei has acknowledged, they are a lot smarter than the ones who beat "black elements" to death in public in the late Sixties, or the thugs who followed me around in my car, a foot from my bumper, headlights blazing, and screamed abuse ("ci mai" — motherfucker) when I protested.