Once a coronavirus success story, Hong Kong is facing its worst outbreak yet, and policymakers are realizing how little they can do without making a bad situation worse.

New infections have broken records on nine of the last 20 days. But unlike other global cities, Hong Kong has been reluctant to impose stay-at-home restrictions or close nonessential businesses. Instead, the rules have gotten incrementally tighter, changing by the week. Public gatherings were limited to four people, then two. Dining-in was banned for dinner, then lunch. Masks were required on public transport, then all indoor public spaces, now everywhere outdoors as well.

The steady drip of half-measures goes against what the short history of the pandemic has shown to work: broad and stringent lockdowns levied early on the infection curve. In Australia and other places currently fighting flare-ups, officials have quickly reinstated tight restrictions.