In March 2022, new Covid-19 variants spread through Shenzhen, Shanghai and other cities in China. For its part, Shenzhen received praise both from the public and the central government for moving swiftly to seal off the city and control the spread of the virus. Shanghai, meanwhile, which has long been known for its relatively humane management of the epidemic, rejected a total lockdown of the city in the early stages of the outbreak, employing instead a “targeted prevention strategy” (精准防控策略) that involved tracking transmission chains, isolating the close contacts of positive cases, and locking down individual neighborhoods and building estates.

As questions about the wisdom of Shanghai’s approach circulated on social media, the city urged residents to take a broader view. One expert from the city’s Covid-19 response task force said on March 26: “I saw one proposal online asking why we can’t make up our minds to lock the city down for three or five days, or even for a week? No, we can’…