What is the message sent by Beijing in sentencing the human rights activist Hu Jia to three and a half years in jail? A decision of this magnitude and its timing, just as the Olympic flame has started its journey around the world, doesn't happen by accident.
Hu Jia has been harassed for the past two years, whisked away from home by security police, stopped from flying abroad, kept under house arrest with plainclothes thugs lurking outside, while his wife, pregnant until their daughter was born last November, was followed and threatened. After he was formally arrested at the end of December, the authorities waited until March 14 (the fourth day of the Tibetan protests) to announce that his trial would start on March 18. That was the final day of the National People's Congress which is supposed to display politics as normal in China.
Hu's persecution began when he was campaigning solely on environmental and social issues. He first became active in Friends of Nature and campaigned to protect the Tibetan antelope from being hunted for its fur. (I met him early on at a small demonstration to protest against building plans on Nanjing's Purple Mountain.) He then became deeply involved in efforts to help the victims of the commercial blood scandal in Henan province when donors and their families were infected with HIV.
It is a mark of Hu's determined character that the effect was not to silence him but to broaden his critique. The joint manifesto (pdf) which he published last September with fellow activist Teng Biao is a remarkable document which ranges from the way that houses have been destroyed without proper compensation for the Olympics to the torture of Falun Gong followers in jail - and it deals with repression in Tibet too.
The Chinese government could still have handled this by continuing to keep Hu under house arrest and preventing any outside contact with him - the way that dozens of other dissidents will be dealt with during the Olympics. So why the high-profile trial and conviction at such a sensitive time?
The charitable view is that the state security apparatus is semi-autonomous and cannot be easily restrained. This alibi has been used in the past - for instance during Clinton's visit to China in 1998 - to distance the top leadership from nastiness.
It is much more likely that the decision to jail Hu was taken deliberately by the politburo standing committee, or a sub-committee under party and state leader Hu Jintao, to send a clear message to the world.
This might be expressed as follows: "China will say no to foreign critics and interference. We are the ruling party, we will not be shaken and will stifle protest with full dictatorial power when our rule is threatened. That for us is still the lesson of Tiananmen Square whatever you may think. We also be as tough as we like in Tibet - and by the way you now depend on us for global economic and financial stability. So just shut up."
Beijing has spoken: how will we respond? And how much longer can Gordon Brown carry on insisting that he will go to Beijing for the Olympics, and when he gets there just lie back and think of two-way trade?