Hong Kong on Friday issued new amendments to its film classification rules, effectively injecting Beijing’s strict censorship standards on the previously liberal territory.

Hong Kong censors previously screened content merely to rate it for typical metrics like violence or obscenity, classifying them into one of three categories to indicate age appropriateness.

Now, they will have to actively intuit what will displease Beijing. and remain “vigilant” in flagging potential national security threats posed by cinematic works, the new guidelines state.

Hong Kong has long been a bastion of creative freedom and freedom of speech, and a haven for artists and dissidents fleeing suppression in mainland China.

Last June, however, Beijing imposed a controversial National Security Law that has allowed it to rapidly dismantle those freedoms. The law has been used to forbid public protests, muzzle the press, jail activists, change the system of elections and, most recently, forbid public commemorations of the June 4 Tiananmen Square crackdown anniversary.

The new film rules have been imposed as part of the NSL implementation process, the official guidelines state. They come into effect on Friday, the same day of their publication.

To comply with the NSL, local censors must be guided by an awareness of the “fundamental importance of safeguarding national security” and the “imperative of effectively preventing or suppressing” any acts that could endanger it, the guidelines said.

They must guard against “any film content that is objectively and reasonably capable of being perceived as endorsing, supporting, promoting, glorifying, encouraging or inciting” destabilizing acts.”

Films whose content or whose very act of screening could be interpreted as “an incitement to secession, subversion or collusion with foreign countries, advocating terrorism, publishing or displaying seditious publication” should be banned from exhibition, it stated.

The document framed the new regulations as essential for the public good. The measures will help Hong Kong balance the “protection of individual rights and freedoms on the one hand, and the protection of legitimate societal interests on the other,” it stated.

It explained: “Although fundamental rights including the right to freedom of expression… should be respected, the exercise of such rights may be subject to restrictions… that are necessary for pursuing legitimate aims such as… the protection of national security or of public order, or of public health or morals.”

Although the new guidelines mark a shocking about-face for cinematic freedoms in Hong Kong, and were seemingly announced without giving the film industry a chance to provide feedback, they do not come as a surprise.

In March, the sold-out theatrical premiere of protest documentary “Inside the Red Brick Wall” was pulled at the last minute after the venues were pressured by pro-China media outlets. Days later, the big-budget Hong Kong-mainland co-production “Where the Wind Blows” was pulled from its spot as gala opener at the Hong Kong International Film Festival for “technical reasons” — a euphemism for Chinese state censorship.

In April, the island’s top network TVB declined to televise the Oscars for the first time since 1969, even though Hong Kong’s submission “Better Days” had the rare honor of being nominated for best international film. The decision came after Beijing ordered its channels to do the same, given that one of the nominated documentary shorts, “Do Not Split” chronicled Hong Kong’s pro-democracy protests.

Last week, in what was a clear fore-runner of Friday’s announcement, local censors admonished a trade union for organizing screenings of two Tiananmen Square-related films. It warned the group that one of the titles had not yet been rated by censors, and the other was set to screen in a venue that had not been issued a letter of approval, which could result in fines.

Filmmakers have reported difficulties finding finance or crew for projects that could conceivably touch on subjects deemed politically sensitive by Beijing. Increasingly, residents are even afraid to accept press interviews or show their face TV news.

The new changes to the film censorship rules do not mean, however, that Beijing itself is directly carrying out the task. For the time being, films seeking the right to screen in Hong Kong will still ostensibly be vetted by local bureaucrats, not the mainland’s Film Bureau or propaganda authorities.

Given the rapid rate at which Hong Kong’s freedoms are being eroded, however, time will tell how long this particular version of “One Country, Two Systems” will endure.