Looking back, we can see that it all began on January 14th. That was the day when President Jiang Zemin gave an internal party speech calling for "vigorous and dynamic" resistance against party members and cadres "openly expressing opposition in newspapers, books, and speeches to the party line and general and specific policies."

The address, in which the Chinese leader also railed against an alleged plot by the US-led developed world to "Westernise" China, was not made public until April 7th, but by then it was becoming clear that a purge of outspoken academics and editors was under way.

Four of the country's top academics were fired from the Chinese Academy of Sciences for criticising current policies; the editor of China Business magazine was sacked for being too pro-business; and the Jiangnan Times in Nanking was closed for three days for reporting too many details of the murder two weeks ago of a German businessman from Daimler Chrysler and his wife and two children, an event which alarmed the expatriate community in normally safe China.

Criticisms of the academics were spelled out last week in a party newspaper, the Guangming Daily. In a manner reminiscent of political struggles of long ago, it accused them of teaching too many Western ideas at the expense of Marxist ideology.

Those ousted included Mr Fan Gang, the highly regarded director of China's National Economic Research Institute; Mr Mao Yushi, a respected economist; Mr Liu Junning, a liberal political science professor who had called for greater democracy; and Mr Li Shenzhi, a retired vice-president of the academy - whose real sin was to voice his thoughts on the Internet.

The Chinese leadership is desperately concerned about the impact of the Internet on political debate, and the article posted on a website by Mr Li, who is also president of the China Society for American Studies, appears to have offended Mr Jiang. In it, Mr Li scorned the sacred trappings of the October 1st anniversary celebrations in Beijing, saying only North Korea could envy the triumphal parade of tanks, soldiers and smiling children. This article precipitated President Jiang's January speech.

However, the purges were not that serious. Mr Fan and Mr Mao, for example, continue to run consulting firms and no one has been taken to the gulag. Many Chinese people are in fact asking just what these ideological knuckle-rappings were all about, at a time when the country is facing more serious problems relating to laid-off workers, rural unrest and corruption.

One well-informed observer said he believed the purges were the actions of an outof-touch party which believes critical debate threatens its authority and ultimately its existence. Beijing, he said, is afraid that published criticism might fuel dissent and unrest.

The fear of unrest is real. There were very serious clashes in the north-eastern mining town of Yangjiazhanzi in February, when thousands of miners smashed windows, wrecked cars and fought with armed police for several days before the People's Liberation Army moved in and ended the affray by firing in the air. The disturbances stemmed from an announcement that a mine was bankrupt, and that the 20,000 laid-off workers would not get welfare benefits, only a once-off severance payment. News of the riot was broken by the Financial Times last week. It has still not been reported inside China.

This is the sort of industrial agitation which could occur again as state-owned enterprises go bust in the face of outside competition, especially if and when China joins the World Trade Organisation. Already a wave of unco-ordinated protests has swept towns in the rust belt of the north-east over unemployment and failure to pay benefits.

Mr Jiang's Marxist rhetoric has been taken by some analysts to mean a slowing of economic reforms, but the opposite is happening. The government is pressing ahead with its tough programme of industrial reconstruction, and thousands of plants and mills face closure this year. This takes real commitment to reform. The worst thing that could happen is for China to fail to gain admission to the WTO, said one Western economist. That would really set the clock back.

And despite the action taken against academics, articles continue to appear criticising the authorities. In Thursday's China Daily for example, a senior economist, Mr Wu Jinglian, reproved the government for continuing to allocate two-thirds of the economic resources to a state economy which produces only one third of the gross national product.

A low level of political debate is also tolerated on Internet chat rooms, including "Strong Power Forum" (www.qglt.com) which is run by the official People's Daily, and cheeky criticisms of the government and party can appear briefly before being edited out.

By striking out at those in the party who dare say the obvious - that growth can be guaranteed in the 21st century only through free access to global information and a government that enjoys reasonable legitimacy - President Jiang is admitting that he has no real arguments against political evolution other than an obsolete set of Marxist dogmas, said a Western diplomat.

His campaign of purges and censorship is widely seen as a symptom of a coming crisis for a party unable to change with the times, when economic rules are being revised at lightning speed. Marxism means little to the new generation of Chinese who are driving the private sector on which China now relies for growth.

One often hears Beijing officials say they are determined that China should not go the way of the Soviet Union. The USSR broke up because its infrastructure was crumbling, it had no inward investment, its economy was shrinking, there were big popular opposition movements and an alternative leader was waiting in the wings.

There is nothing like that happening in China, which, moreover, is economically viable where the Soviet Union was in a state of total collapse. In the opinion of academics sympathetic to their purged colleagues, China has its best chance ever to move to accountable government without serious turmoil, and the leadership is shirking the challenge.