A quarter century ago today, in Beijing's Tiananmen Square, nothing happened.

That's right. Typing in '6/4' or other sensitive queries, a mainland Chinese today would find very little on her cursory internet search. Digging a little deeper, she might turn up 'political disturbance'. If she were more determined and used a VPN service to bypass the Great Firewall, only then could she see Tank Man. 'Tiananmen' is a taboo topic in China, and the sensitivity seems to rise every year, especially on this 25th anniversary.

But outside mainland China, 'the incident' (as it is known) is memorialised, and there is a lot to be understood from these observances.

Every year on the evening of 4 June, in Hong Kong's Victoria Park, thousands or tens of thousands (oddly, police and organisers never seem to agree on the turnout) gather for a quiet candlelight vigil. This year, an especially large crowd is expected. That Hong Kong — a special administrative region under Beijing — allows such freedom of political expression is, in itself, positively remarkable. Democracy advocates want to keep alive the memory of Tiananmen lest Hong Kong lose its own liberty. A patriotic counter-rally, which seems to get more numerous and well organised by the year, turns up with pro-government banners. A similar dynamic plays out more noisily in Taiwan, which has its own internal struggle over authority, sovereignty and ties with China.

It is a striking contrast with the mainland, where there will be no remembrance, just thousands of edgy police pacing the Square. Tiananmen has thus become the emotional lens through which people view all Chinese politics. But it is a flawed prism, for Tiananmen is a complex and troubled topic.

I worked in Beijing during those strange, quiet years of the early 1990s. That was when Chang'an Avenue was still a swirl of bicycles and the Great Wall Sheraton was the most lively place in town. If Chinese were traumatised by the events of 1989, they didn't show it. If anything, Beijing felt less oppressive than it does today. The young people working with me had no interest in history; they looked forward. Even today, there seems to be a genuine lack of interest in the recent past, and it is true that most Chinese are satisfied with — or at least they respect — their social compact with the Communist Party.

Some of the icons of the Tiananmen student movement turned out to be not so heroic or principled after all (superb profile here). Many of my Chinese peers, including some who grew up among them and who also went to America, despise the student leaders. They are variously viewed as traitors, mercenaries, or (worst of all) phonies. The diverse reaction to Tiananmen, its actors and its aftermath says much about the complicated political currents running through Chinese society. Of course, many of the middle-class Chinese who have benefited from the Communist Party's stability and the twenty-fold increase in GDP since 1989 are naturally disposed to the status quo. As ever, the rural revolutionary elites have become the new urban conservative elites.

The Chinese as a nation don't welcome rebellion and luan (chaos). Hong Kong's candlelight marchers, ostensibly the ones who care most about democracy, number just a few percent of the population. Pragmatic Hong Kongers would more likely be enraged by, say, a bank collapse, or a real personal infringement of their rights. Indeed, half a million did march in 2003 against Article 23, a new 'state security' law promulgated by Beijing. This was a rare 'don't tread on me' message from an historically apathetic population. Article 23 lies dormant for now, and Beijing seems in no hurry to propose it again; after all, it is hardly facing a crisis of sedition and subversion in Hong Kong. On the mainland, social unrest, by the Communist Party's own admission, is widespread and rising, but is directed largely at local issues like pollution, not at the Party's central authority.

Perhaps the strangest thing is this: given the legitimacy today of China's government, why is it so deeply sensitive about Tiananmen? Even at the time, the Party 'knew it had little to fear from reprisals by the United States, which it predicted would take no real countermeasures.' Wouldn't public trust actually be enhanced by an truthful assessment of 1989? Certainly most Hong Kongers think so. I suspect the verdict of many Chinese would be something like that of the American Civil War: it was a terrible tragedy but it was necessary for the long-term stability of the country, and it has been vindicated by sheer achievement.

Perhaps Beijing fears a reconciliation over Tiananmen might unravel into a broader inquiry into events like the Cultural Revolution and the Great Leap Forward. Perhaps, after all, it is best to let sleeping dogs lie. Yet there is a danger in the deliberate erasure of historical memory, one that is brilliantly witnessed by David Satter in post-Soviet Russia. Ignorance descends into nihilism, and nihilism into brutality. The ongoing stalemate over national history textbooks here in Hong Kong is partly about how to view Tiananmen and its legacy. An honest reckoning still seems far off.

Photo by Flickr user 69.