Two decades might seem like a long time for the memory of Tiananmen to stay so strong in China and around the world.
But the crushing of China's democracy movement was so brutal, and so closely followed by television viewers in so many countries, that it remains one of the most vivid moments of recent history.
The first astonishing thing about the drama, which lasted more than six weeks before culminating on the night of June 4, was the suddenness and size of the pro-democracy protest itself.
It began in mid-April with a popular outpouring of grief at the death of former Communist Party leader Hu Yaobang, a reformist who had been ousted from power and publicly humiliated by hard-liners two years earlier. Supporters headed to Tiananmen Square to pay their respects and then dispersed again.
A week later, they were back, now almost 100,000 strong for a pro-reform protest focused on ending official corruption. The protests quickly spread to other cities and the Communist Party grew alarmed.
As an estimated 1 million-plus students and workers joined the movement across China, Tiananmen Square became the front line. The protesters set up a tent city, called for greater democracy, and vowed not to leave until their demands were met.
As international media flocked to the scene, it was clear China was at a crossroads.
A Party Divided
At stake was whether the party, which had begun allowing people to have private businesses, would let them share some political power as well. That power, like the country's big state firms, was exclusively in the hands of the top party officials and their close relatives -- fueling the protesters' charges of official corruption.
At first, the party leadership split over how to deal with the challenge. Party leader Zhao Ziyang, a reformist, urged restraint and appealed in person to the students to end their occupation of the square. But Premier Li Peng accused them of trying to overthrow the government and declared martial law.
The split within the regime ended in the purge of Zhao and the rest of the party's reformist wing. Deng Xiaoping became the new party leader and he ordered troops from other areas of China into Beijing to suppress what was now officially termed a "counterrevolutionary riot."
The end came quickly, beginning on June 3. As the troops sought to move in, students joined by many ordinary Beijing residents sought to stop them some several kilometers west of the square.
The troops opened fire, killing hundreds. Some protesters fought back by hurling firebombs onto the tanks in an effort suffocate their crews. It was there that most of the people who died in the pro-democracy protest were killed.
The next night, on June 4, the troops advanced on Tiananmen Square itself, which was occupied by thousands of people. The army switched off the lights, plunging the square into darkness, and the tanks rolled forward. As the protesters fled, an unknown number of them were killed in the surrounding streets.
Today, the storm of international protest that erupted over the killings and the subsequent arrest of dissidents has subsided. Beijing hosted last year's Summer Olympics and the games passed largely without Western criticism of China's human rights record.
In the run-up to this year's 20th anniversary, China has taken strict steps to keep foreign media coverage of Tiananmen out of the Chinese public's sight. Government agencies are banning delivery of foreign newspapers and disrupting satellite news broadcasts as well as censoring the Internet.
But there are many signs that memories of the crackdown have not faded in China.
Dissidents issued a declaration in November, called Charter '08, modeled on Charter 77 in the former Czechoslovakia and calling for a "free democratic and constitutional state." The organizer, writer Liu Xiaobo, was arrested. But the 303 China-based dissidents who signed the charter hope it will rally the country's democracy supporters.
Activist and human rights lawyer Li Baiguang, a Charter '08 supporter in China, told Reuters in an interview that “the entire government has become stronger and stronger over the last 20 years, but the strength of the ordinary citizens hasn't grown at all. It shows how naive we were at the time.”
"Now faced with such a powerful government, how can we build democracy?" Li asked. “From the inside -- building the rule of law, protecting people's rights, and using the law to tame the government."
This year, dissidents organized the foreign publication of a book they believe will strengthen their calls for justice on the government's suppression of the democracy movement at Tiananmen. The book is the secret memoir of the Communist Party leader who tried hardest to urge restraint, Zhao Ziyang.
In the memoir, published after Zhao's death in 2005, he directly challenges the regime's continuing assumption that multiparty democracy cannot be allowed for many decades because China's economic development must continue to take precedence over political reform.
"If a country wishes to modernize, not only should it implement a market economy, it must also adopt a parliamentary democracy as its political system," Zhao wrote.
The question now is whether a new generation of Chinese students will read these echoes from Tiananmen Square – and perhaps agree with their conclusions.
Crackdown On Tiananmen Square
June 3rd and 4th mark the 20th anniversary of the Tiananmen Square Massacre, when the Chinese military violently crushed pro-democracy demonstrations. On June 5th, cameras captured the famous image of the lone citizen who stopped a line of tanks. Video by Reuters. Play