Such comparisons reveal how seriously Beijing views the unrest in Hong Kong, which had long been one of the most stable places on China’s periphery. In a move that was part public relations exercise and part threat, People’s Liberation Army troops that are stationed in the city jogged out of their barracks last weekend to “voluntarily” clean the streets, bearing brooms and plastic buckets. It was only the second time since 1997 that they have been seen on Hong Kong’s streets, and it was not lost on Hong Kong’s residents that these soldiers were from the top counterterrorism unit, a designation emblazoned on their colorful jerseys.

The mini-constitution that governs Hong Kong, the Basic Law, stipulates that troops can be called out to help with disaster relief if requested by the local government. In this case, no request had been made. Even if the troops remain in the barracks in the future, their presence has now been advertised, and this contributes to the perception of a militarization of Hong Kong’s streets, which nightly — and increasingly by day, too — teem with regular police officers, riot policemen and members of the elite “Raptor” unit, a specialized riot control task force.

To Chinese readers, mentions of separatism and terrorism invoke Xinjiang, the northwestern province where China is holding an estimated one million members of the Uighur minority in political indoctrination camps. The discourse of pathology is often used in relation to Xinjiang, where Islam is depicted as an ideological illness. One China Daily opinion essay expanded on the comparison, explaining: “The problems of Hong Kong and that of terrorism have similar causes: lack of realistic economic opportunities and misguided ideology. Regarding terrorism, China has shown the world a more effective and humane approach than that pursued by other countries.”

According to this logic, a “weakened immune system” is a vulnerability that can be healed only by the education of “corrigible” but misguided youngsters, raising the chilling prospect of some form of Xinjiang-style ideological re-education in Hong Kong. However, an attempt seven years ago to introduce courses in “national and moral education” to Hong Kong failed after mass protests by students.

These disease metaphors underline Beijing’s view of Hong Kong’s protest movement as a threat to its body politic, with ideological infection posing an existential danger to the Chinese Communist Party. Such discourse could prefigure new restrictions on speech in Hong Kong, a possibility that seems to be inching incrementally closer. An injunction that has been introduced to protect Hong Kong police officers from “doxxing” — releasing their personal details online — has been criticized as overly broad, since it also prohibits “harassing, threatening, pestering or interfering” with the police. Such a law could even technically outlaw singing protest songs about the police. More worrying, one adviser to Hong Kong’s government has already warned that an internet ban has not been ruled out.