Covid-19: What went wrong in Singapore and Taiwan?

They've been hailed as virus success stories - places that have seen virtually zero or single-digit Covid cases since the start of the year. But this month, Singapore and Taiwan have both seen a sudden and aggressive rise in cases - with Singapore logging 248 new cases just last week, and Taiwan 1,200 local infections. Both places have gone into a heightened state of restrictions, limiting the size of social gatherings and closing schools. By global standards, these numbers may seem small - but for these places, these figures would have been unthinkable just months ago. So what exactly went wrong?