In some respects the Chinese authorities can be pleased. Seven years after this officially sanctioned bout of mass murder, the country is not about to explode. Meanwhile, China has been economically transformed in only a few years. In contrast to chaotic Russia, changes have brought a sharp rise in living standards. Huge areas still suffer from devastating poverty, but there is a widespread perception that things are changing for the better. Which, in the purely economic sense, is true. Certainly, the transformation of southern China, the boom region, is a sight to behold. The "special economic zone" of Shenzhen has become a mini-Hong Kong. "Fifteen years ago, this was just rice fields," says a Chinese entrepreneur, as we wander in dazed wonderment amongst the mirror-glass skyscrapers. Here, the world of Maoism has turned upside down.
Portraits of the shrunken but still-powerful Communist emperor, Deng Xiaoping - scarcely seen in public nowadays, and perhaps more dead than alive - hang in the centre of Shenzhen and in Canton, the regional capital, as a reminder of Deng's visit to the south a few years ago, and of the patronage for the new market economy which that now famous visit implied.
Elsewhere, too, the economic changes have continued apace. Shanghai, the country's financial capital, radiates a sense of self-belief. New skyscrapers spring up, as the Chinese saying has it, like bamboo shoots after spring rain. Nor is it only the obvious places that are booming. Go to Wuhan in central China, not usually thought of as an economic powerhouse, and the signs of transformation are all there, too - more building sites, more shopping malls, more skyscrapers.
The excitement about China's latest great leap forward is understandable. And yet there is no certainty that the economy will continue to grow at the remarkable rates of the past few years, when annual growth of 10 per cent has come to seem normal. Sooner or later, the government must face the problem of what to do about dismantling its giant state enterprises, which still weigh down the economy. The official view is that a kind of welfare fund can be created by the newly affluent China, which will cushion the blow when closures finally become necessary. Everybody will then live happily ever after. Most economists believe that this is what it sounds like: a cute fairy-tale. Thus, the government - which already faces scattered outbursts of labour unrest - may be living on borrowed time. Without a powerful mandate, painful economic change is difficult to impose.
At the heart of the problem is the asymmetry between the economic revolution, on the one hand, and political stagnation, on the other. Admittedly, as one China-watcher notes, "The Chinese find it easier to live with contradictions than others do." None the less, the imbalance is clear.
A rubbery Mao, less real-looking than a Spitting Image puppet, is still ensconced in his giant mausoleum in Tiananmen Square; his solemn portrait still hangs at the north end of the square. Odd, but logical. If the authorities start dissecting the legacy of Mao, then everything else could unravel, too. Hence the silence that surrounded the recent 30th anniversary of the Cultural Revolution, when destruction became a political imperative. Impossible to praise, impossible to condemn - easier just to forget it. This failure to discuss the past is intimately bound up with the unhealed wounds of Tiananmen Square.
For students, let alone for ordinary Chinese, the traumatic events of Tiananmen do not top the current agenda. Even in private, former protesters talk of that period as a closed chapter. Partly, that is because of well grounded fear: those who launched petitions in the lead-up to yesterday's anniversary were promptly arrested. Partly it is because the brave new world of business offers opportunities for the well-educated to become prosperous, and thus bury the past. Partly it is a waiting game.
Chinese officials justify the suppression of discussion in two ways. First, "People do not want to talk about this, nowadays." Partly true. But this is often backed up, by a second, contradictory argument: "Everybody would argue about it too much. That would not be good for the country."
And there lies the rub. The Chinese warn constantly of the danger of luan, or turmoil. The popular fear of luan is often quoted as a reason why nothing will ever stir. And yet the official acknowledgement of the underlying restlessness - if the floodgates were opened tomorrow, then millions would be discussing Tiananmen and heaven knows where it would all end - is a reminder that everything might yet change. The Chinese authorities hope that the memories of Tiananmen will gradually fade like a forgotten scar. And yet a failure to address the past can itself be a recipe for luan.
In the Soviet Union, glasnost without perestroika proved a spectacular failure. By 1991 Russians had almost complete freedom of speech but the Communist economic system was scarcely shaken or stirred. It was a recipe for disaster. In China it is still unclear whether the reverse combination, perestroika without glasnost (copyright-holder: Deng Xiaoping), can work any better, in enabling a totalitarian regime to survive.
Already the paradoxes are clear. One can sit in a Chinese factory listening to the director waxing lyrical about export-oriented production, the fabulous relationship with foreign partners, the joys of the market economy. And then you notice the Communist slogans on the wall. Oh yes, says the factory director (and party cadre), the Communist Party is "very important" for the factory's work. Ask if the Communists might one day perform the same kind of backflip on politics as they have so enthusiastically performed on the economy in recent years and you get an icy stare. "That is off the topic," says the previously gushing director after an ominously long pause.
Comparisons are always dangerous. None the less, if one looks at other countries where repressive regimes have collapsed under their own weight, there is little comfort for the Chinese government. Any government that raises living standards reaps political benefits. Thus the West raved about economic growth in Poland under Edward Gierek in the Seventies; the Poles, too, were happy. But the moment the downturn began things turned sour. Four years later, Solidarity, the grassroots movement that eventually toppled the Communist state, was born. The catalyst: price rises on selected meat products.
Apathy, too, is a curious beast. A traumatic event can appear to be left behind, even while the wound still festers. After the Soviet invasion of Czechoslovakia in 1968, people were numbed for 20 years. Dissidents such as Vaclav Havel were isolated and even reviled, as most Czechs showed more interest in beer, sausages, and a nice apartment than in reversing the legacy of the tanks. Conventional wisdom had it that they would never rebel again. Then, in August 1988, a few thousand Czechs staged a dress rehearsal for the velvet revolution; barely a year later the Communists were gone.
Even fear of luan is not a uniquely Chinese characteristic. The 16th- century smutnoe vremya, or "time of turmoil" is seen as a black and dangerous period in Russian history. That fear of chaos, and love of the "strong hand" was one reason why so many remained loyal to the Soviet state for so long (and they were loyal to the Communist state: not until 1989 and 1990, as everything else fell apart, did the mood seriously begin to swing against the regime itself).
Russia's population is much better educated than China's. But the people in Russia's huge countryside, too, were scarcely in revolutionary mode when Communism crumbled. All that really matters is for the urban government to feel, for whatever combination of reasons, that its position has become unsustainable. Theoretically one can use force to re-establish control - as happened on that fatal night in Peking in June 1989. But even that trick cannot be used too often.
The leaders of East Germany, who had been publicly enthusiastic about the Tiananmen killings, planned a local Tiananmen Square in Leipzig, on 9 October 1989. The orders were given, the hospitals cleared, the city sealed off. All of us who were there that night - a handful of journalists who had slipped through the cordons, and 50,000 protesters - saw the truckloads of armed militias and knew that the threats were real. And then, at the last moment, the authorities lost their nerve: they realised that the threat of force had made Germans, not best known for their rebellious qualities, more defiant, not less. It was the crucial retreat in East Germany. A month later, the Wall was down. In equally unrebellious Romania, by contrast, the dictator Nicolae Ceausescu decided he would go ahead with force. Result: tanks, shooting, deaths - and, within a week, a brace of dead Ceausescus.
One reason for believing that Chinese Communism - the one-party system, the secrets, the lies - will survive is that China is unimaginable without Communism. And yet, in its own terms, that is not much of an argument. The collapse of the Soviet Union was widely regarded as "unthinkable". Ergo, politicians and diplomats refused to think about it, even when you tried to pin them down. Logic and the constantly changing mood on the street pointed in only one direction ("The crumbling of an empire," in the words of an Independent headline seven months before the Wall came down, and "The Kremlin cannot put the lid back on", seven months before the Soviet coup). But it was assumed that because the Soviet system had been around for 70 years, it had somehow gained itself a a certificate of eternal life.
The eruption of Tiananmen Square itself - a million people, gathered at the heart of the Chinese capital to demand change - was neither predicted nor predictable. Equally, no future set of changes can be predicted, in the literal sense. Nobody knows the precise effect of the flap of a butterfly's wings, which might unleash a political hurricane. But there are tiny signs. Seven years after Tiananmen people are willing to talk with a stranger about those events, saying that they would not have dreamed of doing so just a few years ago. That cautious opening-up may in itself may prove to be an important change.
Further radical change seems certain to come - not necessarily all peaceful, or comfortable. Thus political change might bring pressures on the Chinese state itself, which includes a permanently restive Tibet, and an increasingly restless Xinjiang province, with its large Muslim population, in the north- west.
There is continual speculation about the leadership changes that might follow the death of the 91-year-old Deng Xiaoping. But Great Hall-ology may prove as useless as Kremlinology was, in answering the bigger questions. These, after all, will not just be settled by a little band of old men within the walls of Zhongnanhai, the Communists' own Forbidden City, in central Peking. The hidden changes in Chinese society itself will be crucial.
The Chinese have no experience of democracy. But nor did the Russians, who now have a messy version of a multi-party system. Taiwan, meanwhile, has moved from locking up dissenters to a little greenhouse version of Chinese democracy in action. In other words: neither huge, traditionally undemocratic countries, on the one hand, nor ethnic Chinese, on the other, are genetically preprogrammed to live in untruth.
Chinese businessmen are now encouraged to make their own capitalist deals - by fax, phone, e-mail and in person - with the old enemies: with Taiwan, Britain, the United States and all points West and East. And yet, if they talk openly about the events that shook their own country, seven years ago, they can be locked up. That is both mad and bad. And there is no good reason to suppose that it will last.
All the more depressing, then, that Michael Heseltine, the Deputy Prime Minister, did not see fit to pursue the question of human rights when he recently met Li Peng, Prime Minister and chief slaughterer of 1989, in Peking. People in power always assume that other people in power are the only ones who matter. That is not just morally dodgy, but also politically wrong. Watch for the flapping of a butterfly's wings. And wait for the hurricane.