A police officer patrols outside Legislative Council building in Hong Kong on Tuesday. (Vincent Yu/AP)

THE LESSONS of recent events in Hong Kong start with the fact that an enormous number of people took to the streets in peaceful demonstrations against a rollback in the territory’s guarantees of freedom and autonomy from China. The very size of the protests that filled Hong Kong’s downtown, the largest in a generation, is a powerful reminder this is not a splinter movement but the mainstream speaking loud and clear.

Another lesson is that Hong Kong’s protesters are growing angrier and more distraught than they were before. In past years, it often appeared the opposition in Hong Kong was unfailingly orderly, simply asking China to fulfill its original promise to protect Hongkongers’ freedoms. There was little public support for outright independence from China. But the latest demonstrations reflect a new edge of distrust and wariness that should worry the rulers in Beijing.

The militancy is a direct result of China’s gradual but inexorable tightening of the screws on Hong Kong, most recently through a proposed extradition law that would have undermined the territory’s justice system. China’s leaders, who supervise the Hong Kong executive, have no one but themselves to blame for the opposition’s hardened attitude.

In the most recent protest, furious young people broke into the offices of the Legislative Council, or Legco, smashing windows and vandalizing the chamber with spray paint. China immediately reacted by labeling the intruders “extreme radicals” and saying they carried out “a series of large-scale assaults” that are “totally intolerable.” This may be just the initial knee-jerk reaction of China’s propagandists. The leadership in Beijing should look deeper. The fury of these young people is a result of pent-up frustration that previous efforts had failed to halt the slide in Hong Kong’s freedoms. They were incensed when, following the mass protests, the extradition bill was suspended but not canceled altogether.

“The Hong Kong government was pushing us to the point of despair and desperation,” said Joshua Wong, a leader of the 2014 protest movement, on Twitter. “We tried every possible way imaginable to make our voices heard.” Graffiti scrawled on a wall in the Legco said, “You taught me peaceful protests are futile.”

The young people must be careful not to give the Chinese Communist Party leaders in Beijing, or their underlings in Hong Kong, an excuse for more repression. Violence and vandalism invariably play into the hands of the Chinese leaders, who take fright at all signs of protest and democracy. In today’s world, the students can be just as powerful hurling words as smashing windows.

The larger conclusion to be drawn is that China’s leaders should abandon their old thinking. Repression will ultimately fail and generate more resistance. China can’t grind down Hong Kong for another generation, and it would be terribly counterproductive to try.