Many politicians and public health officials sounded a similar lockdown refrain in the spring: let’s do this right so we only have to do it once.Reality check: While some countries have thus far managed to keep cases under control after opening up, dozens of countries that had initially turned a corner are now seeing a worrying rebound. They have to decide if and how to return to lockdown — and whether their populations will stand for it.Driving the news: Protesters have gathered again tonight in Belgrade, Serbia, following two nights of violent clashes. The tumult began after a sudden uptick in cases led President Aleksandar Vucic to announce a new coronavirus curfew.Serbia had initially avoided a major outbreak but lifted what had been one of Europe’s strictest lockdowns in early May and began to allow crowds to pack into sporting events and bars. Parliamentary elections also went ahead in June.Vucic’s critics claim Serbia reopened too rapidly and is now paying the price. Protests both nights began peacefully but ended in violence, some of it inflicted by police.Where things stand: Vucic has backed down, but gatherings of more than 10 people will be banned and indoor venues will have to close early.Japan has also seen its case count — long strikingly low given its large, dense population — tick upwards in recent weeks.Economy Minister Yasutoshi Nishimura denied yesterday that there was any need for a new state of emergency. Reopening plans, including allowing some fans back in stadiums, are moving ahead.The government’s primary focus is the economy, as was demonstrated by the replacement of a panel of scientific experts with a new body that includes business leaders, the Washington Post notes.Officials point out that many of the new cases are among younger people, death rates remain low, and hospitals aren’t under strain.Other countries have been quicker to react to spikes. Melbourne, Australia entered six weeks of lockdown after a record-high 191 infections were recorded in the state of Victoria on Tuesday.Prime Minister Scott Morrison said Australia’s second-largest city was sacrificing for the whole country so that its outbreak would be contained there.Chinese cities, including Beijing, have also seen quick snapbacks as the government attempts to confine outbreaks to one location.Several European hotspots — Leicester in the U.K., Guetersloh in Germany, parts of Catalonia and Galicia in Spain — have re-entered lockdowns.The Israeli government is considering neighborhood-level restrictions, as its success at containing the virus seems to be unraveling.Targeted restrictions have already been applied in 19 Lisbon boroughs, a few Rwandan villages and a single building in Italy, per CNN.These small-scale clampdowns could help countries avoid the deep economic harm of the first lockdown wave.What to watch: It has been exactly four months since the first lockdown outside of China was announced, in Italy. It will likely be far longer before a vaccine is widely distributed.Some countries may avoid major new outbreaks. Others, particularly in the developing world, will reject new shutdowns even if they don’t.The bottom line: We can expect to see many cities, and perhaps countries, dancing in and out of lockdown in the months to come.