“Contemplating the opening of borders in Europe today will earn you a “what a lunatic” label. Just as COVID-19 can be exacerbated through underlying health problems, the European free-movement zone’s own pre-existing conditions put it at great risk.
Before the coronavirus scare, there were already any number of motivating factors for European countries to reintroduce borders – migration flows, terrorism and cross-border crime, and the Europe-wide inward-looking tendency to seek national solutions.
These inclinations will only get worse with COVID-19. If these issues continue to be left unattended, we will have a Europe (and an entire world) where borders are more stringent and more persistent than what we are used to.”
See: Return to borderless Europe after COVID-19 will be difficult but not impossible (EurActiv, link)