China officially has the broad power to quash unrest in Hong Kong, as the country’s legislature on Thursday nearly unanimously approved a plan to suppress subversion, secession, terrorism and seemingly any acts that might threaten national security in the semiautonomous city…

Early signals from Chinese authorities point to a crackdown once the law takes effect, which is expected by September.

Activist groups could be banned. Courts could impose long jail sentences for national security violations. China’s feared security agencies could operate openly in the city.

Even Hong Kong’s chief executive this week appeared to hint that certain civil liberties might not be an enduring feature of Hong Kong life. “We are a very free society, so for the time being, people have the freedom to say whatever they want to say,” said the chief executive, Carrie Lam, noting, “Rights and freedoms are not absolute.”