Just before the evening news in Hong Kong on a Monday in July, Asia Television (ATV), one of the city’s two free-to-air TV stations, was showing a documentary produced by China Central Television (CCTV), the state broadcaster.

The screen showed grainy old images, shot during the 1950s, of workers clearing a road through Tibet’s mountainous landscape. The narrator explained that “Chinese and Tibetan soldiers and civilians worked shoulder to shoulder”, building highways that turned Lhasa “into a modern city overnight” and “made Tibetan butter tea an affordable luxury for the province’s grateful citizens”. It is a picture of fraternal harmony that accords ill with the riots and deaths in the country this March, but one well attuned to the antennae of the rulers of Hong Kong, back in Beijing.