A SHORT WALK from Tiananmen Square, young carworkers wearing company tracksuits stand with their fists in the air. They are renewing their vows to the Communist Youth League by chanting promises to “resolutely support” the Communist Party and “strictly follow” the league’s regulations. When they step aside for a group photo, 40 students from a technical college take their place to make their own pledges of loyalty. A growing queue of youngsters waits nearby to do the same.

The oath-swearing spot is in the courtyard of an imposing edifice of russet brick, known as the Red Building. A century ago it belonged to Peking University, one of China’s most prestigious seats of learning (now in a north-western suburb). There is a striking contrast between these professions of faith in a dictatorial party and an exhibition the same young people are taken to see inside the building. It is about the students who, 100 years ago on May 4th, set off from the Red Building and other sites around the city to join a protest at Tiananmen provoked by the shabby treatment of China by its allies after the first world war. The Treaty of Versailles had awarded a former German colony in China to Japan.

Today May 4th is officially celebrated as Youth Day. Its significance is strongly contested. The party recalls the May 4th Movement, which refers to the protest in Tiananmen as well as similar ones elsewhere in China and intellectual soul-searching around that time, as the backdrop to the party’s birth two years later. Liberals remember the movement as a cry for democracy by patriots who believed that China had no hope of standing tall without adopting Western learning, including in politics. In a year packed with sensitive anniversaries—including the 30th on June 4th of the army’s crushing of student protests in the same square in 1989 (an event barely known to many young people in China, owing to the assiduous efforts of censors)—the party is bent on ensuring that its version of history is the only one heard.

Both the party and dissidents agree that in 1919 the country was at its nadir. The last imperial dynasty, the Qing, weakened by decades of internal strife and foreign encroachment on Chinese territory, had collapsed in 1911. A military strongman, Yuan Shikai, had tried to reinstate the monarchy with himself as the new emperor. His death in 1916 had unleashed struggles between rival warlords. The young protesters had hoped that China’s support for the allies against Germany—it had sent about 140,000 men to work as labourers on the front in Europe—would result in the return to China of colonised territory. Not only had their hopes been dashed, but, as they saw it, China’s own government had been complicit in the betrayal.

But the party prefers not to delve deeply into the political aspirations of the May 4th Movement, including the view of many participants that China’s weakness was in part the result of flaws in its traditional culture. China’s current leader, Xi Jinping, is trying to recast the party as a champion of ancient Chinese values. The reformers of 1919 would be horrified.

There is only one aspect of the movement that officials want to dwell on, namely its links with the party’s founding, says Rana Mitter of Oxford University. But public discussion even of the party’s early ideals is curtailed. The party does not want to be reminded that its supporters were once attracted by its promise of liberation from autocracy, not by the dictatorship it came to represent. In recent decades the party has downplayed the iconoclasm of the May 4th Movement, preferring to portray it as something far blander. A student leader tells one of the groups outside the Red Building that “the spirit of May 4th” is today found in young doctors who battle epidemics and young soldiers who rescue citizens from natural disasters.

If there is something galling about a government that brooks no dissent making heroes of long-dead protesters, no one at the Red Building is willing to admit it. China today is far more tightly controlled than it was during the early months of 1989 when the party was almost brought down by students who claimed that they, not China’s geriatric leaders, were the true heirs of 1919. Those protests were fanned by excitement about the 70th anniversary of the May 4th Movement (hundreds of thousands took to the streets on that day 30 years ago—a high point of the unrest). The party frets that the proximity this year of two big anniversaries—of the demonstrations in 1919 as well as in 1989—will encourage dissidents to air their grievances.

Given the intensity of security in the capital, this is highly unlikely to happen on the streets. But the party’s anxiety has some basis. Campus activism has been bubbling up in the form of #MeToo campaigning against sexual harassment and an attempt by self-described Marxists to help factory workers in southern China establish a free trade union. Police have arrested dozens of these labour activists. (Six students connected with the cause are reported to have been taken into custody on April 28th, presumably for fear that they might speak out during the centenary.) Academics are cowed, but not crushed. Lately the bravest have been speaking up for Xu Zhangrun, an academic in Beijing who was suspended earlier this year for attacking Mr Xi’s authoritarianism.

The party can at least claim to have fulfilled one dream of the protesters of 1919: China is now a global power (Mr Xi will be careful to ensure that his trade agreement with America’s president, Donald Trump, expected soon, does not look like surrender). But on April 30th, at a commemoration of the centenary in the Great Hall of the People next to Tiananmen, Mr Xi gave a veiled warning to dissidents. He described being unpatriotic as “disgraceful” and said that loving the country was closely entwined with loving the party and socialism. The traditional May Day public holiday was recently extended from three days to four. The party may hope to nudge Beijingers to enjoy a break outside the city and leave its history behind. The “spirit” of the centenary looks a lot like mistrust and fear.