How border closures halted Covid-19 in Finland

Back in April, I listed five measures governments can take to prevent the spread of Covid in order to prevent any need for economically devastating lockdowns, drawing on the experience of some Asian nations.

Four of the measures (test and trace, healthcare capacity, facemasks, and good communication about distancing) have all proven their worth, but the fifth may be the most important of all: imposing border checks in time.