Dan Southerland is executive editor of the congressionally funded network Radio Free Asia. He was chief of The Post’s Beijing bureau from 1985 to 1990.

Twenty-five years after the Chinese army fired on unarmed citizens defending pro-democracy protesters at Tiananmen Square, China’s Communist Party seems more determined than ever to silence critics who dare to speak out about the massacre.

This year, the government began striking earlier and harder than before at those attempting to mark the highly sensitive anniversary dates of June 3 and 4 .

One would expect more confidence — and the courage to face up to history — from a leadership that has overseen such rapid economic growth since 1989. Analysts say that the party is nervous about social unrest resulting from the abuse of power by authorities, land and labor disputes and a sense that endemic corruption has benefited high-ranking officials and their children.

But when it comes to Tiananmen, the party may also fear something else: the courage of those who refuse to forget the massacre.

If anything, that courage — displayed not only by dissidents, lawyers, artists, and writers but also by ordinary people who lost sons and daughters in the massacre — has grown even stronger over the past few years.

And the party may fear that its legitimacy will be questioned when it becomes clear it had to rule by armed force in 1989, not only in Beijing but in dozens of other cities throughout China.

Thanks to those who persist in researching these issues, we now know more about how this force was used to crush popular protests in cities far from Beijing.

As Beijing bureau chief for The Post in 1989, I reported on the aftermath of the protests in Chengdu, more than 800 miles southwest of Beijing. At the time I heard that at least eight people had been killed in clashes between police and protesters. But thanks to Louisa Lim’s well-documented new book “The People’s Republic of Amnesia,” I now know that witnesses’ accounts indicate the deaths were at least in the dozens.

Meanwhile, a group known as the Tiananmen Mothers continues to courageously and painstakingly document the deaths of their children as well as other victims who were attacked by the army and police. They’ve demanded from the authorities official accountability for the deaths. The party has declined to respond.

The group’s founder is Ding Zilin, whose 17-year-old son was shot and killed in 1989. In previous years, Ding, 77, and her husband had been able to hold private memorial services at their home in Beijing or at the spot where their only child was killed. But this year she was placed under “soft” arrest — a kind of house arrest — in the city of Wuxi, in far-off Jiangsu Province, and she remains there as of this writing.

In the United States, several universities have organized conferences this year focused on Tiananmen. Many mainland Chinese study at U.S. universities, but at most of these events, only a small percentage of those students turned out. Some who participated preferred not to have their pictures taken.

At one gathering at Pomona College in California, some 40 people attended, including about 30 Chinese students. These are, of course, small numbers. But the students asked questions about many aspects of what occurred in 1989.

Thanks to the Internet, many Chinese can now project their voices farther when discussing sensitive issues than once would have been the case. “Resentment of censorship has built,” Xiao Qiang, the chief editor at China Digital Times, said at a recent hearing in Washington. “The connection facilitated by the Internet gives Net-izens a sense of ‘togetherness’ and makes them less fearful of speaking the truth.”

So courageous Chinese are keeping the story of Tiananmen alive. Through their writing, their art, their scholarship and their networking, these brave people break through the “Great Wall of Silence” that surrounds the events of 1989. Human rights lawyers attempt to defend many dissident figures, often at great risk to their careers.

As soon as China’s leaders realize that the legacy of Tiananmen is a burden they must confront and that the worldwide respect they desire will depend on more than military and economic clout, we may see a reappraisal of Tiananmen.

Not this year perhaps. And probably not next year. But someday.

As a reporter who covered wars in Vietnam, Cambodia, the Indian subcontinent and Central America, I came to believe some time ago that every massacre in modern times would eventually be exposed, not only to the outside world but also within the countries where the atrocities occurred.

For those who say that China is different, consider how the Chinese on Taiwan dealt with the infamous Nationalist killings of Taiwanese on Feb. 28, 1947. Taiwan eventually faced up to history, and you can now visit a museum in Taipei that is dedicated to the victims.