Five years ago, when Hong Kong residents flooded the streets to demand true democracy, the movement was named Occupy Central With Love and Peace. On Monday, as a group of protesters overran the region’s legislature, a banner hung outside carried a harsher, more pessimistic message borrowed from the Hunger Games films: “If we burn, you burn with us.”

Half a million had peacefully marched against the extradition bill that day. Even the splinter group who broke into the building, spray-painted slogans and hung the British colonial-era flag had their limits. They put up signs urging others not to damage antiques and left cash for drinks from the cafe. Force was directed at property rather than people. But the angry, destructive scenes nonetheless reflect a hardening of feeling.

The occupation and vandalism will alienate some ordinary residents as well as risking retaliation. One pro-democracy legislator described the ease with which protesters gained entry as a trap; there are fears that it plays into the hands of the Chinese government, which has already described events as “intolerable”.

Yet many of those who opposed the takeover, and in some cases tried to physically prevent it as police stood aside, nonetheless blame authorities rather than those who stormed the building. Hong Kong’s chief executive, Carrie Lam, halted the new legislation after huge demonstrations, but her refusal to withdraw it or to apologise for harsh policing (including the firing of teargas and rubber bullets and beating of protesters posing no apparent threat) has fuelled the anger and sense of hopelessness. “We already tried everything else,” the activist Joshua Wong wrote on Twitter. He was not among those who broke in.

When Hong Kong was returned to China 22 years ago this week, Beijing promised that the region’s way of life would be safeguarded until 2047. But hopes that the mainland would become more like Hong Kong were destroyed long ago. Beijing has made clear its determination to bend the region to its increasingly repressive will. Residents have seen the attempts to push through anti-sedition laws and patriotic education; the harsh sentences for protest leaders and activists; the disqualification of pro-democracy legislators; the muzzling of the region’s media. If the unease in 1997 was prompted by uncertainty, one analyst observed, some of it now comes from certainty.

Jeremy Hunt’s clear support for Hong Kong’s freedoms is welcome after the muted approach of previous foreign secretaries. Britain has a particular duty as the other signatory of the legally binding treaty on the region, which Beijing has dismissed. But it is Hong Kong’s residents who are rallying as never before to defend their rights.

As many as one in four turned out to oppose the bill allowing people to be extradited to the mainland, many regarding it as the last line of defence for the region’s freedoms. The proportion of residents feeling proud to have become citizens of China has plunged to a quarter, the lowest since the handover. Only two in five are confident in the region’s future. One in six now support independence, even if few think it possible.

The trade war has made Beijing more anxious than usual about disrupting Hong Kong’s economy, but this is merely a question of patience: in the end, politics trump economics for the Communist party. The underlying dilemma has not changed. Do nothing, and the encroachments will continue; resist, and prompt retaliation.

That fear of retaliation has shaped this leaderless movement, whose advantages are real but whose perils are equally evident. Its participants are drawing different conclusions from the same underlying calculation: Hong Kong cannot overturn this dynamic. The question is how best to prolong it, hoping that China one day changes.