On any digital dashboard tracking the spread of Covid-19, on any graphic comparing country-by-country case curves or death tolls, they were the champs. Singapore, Hong Kong, Taiwan, South Korea—leaders there saw what was headed their way from China in the early days of the new coronavirus, before it became a pandemic. They remembered what happened two decades ago with SARS: People died, economies suffered. So they locked down their immigration hardest and soonest, deployed public health workers to follow up contacts of cases, got their hospitals shored up, and started publishing clear and consistent information and data. They flattened their curves before the rest of the world understood there would be curves to flatten. But in recent weeks, those curves have taken another chilling turn. The numbers of new cases in these places are creeping upward.