Biggest challenge for the post-COVID19 world will be the re-opening of borders. I doubt countries will blanket open all borders on a given day. They’ll do so selectively, first to some countries, then others. Some countries may be frozen out for a long time. 1/3

Without open borders, there are no flights, limiting logistics. Countries will require periods of quarantine from visitors from some countries, but not others. This will lead to a global realignment. Countries that depend on tourism will be hard hit for a long time. 2/3

Every border opening will be a political statement. For instance, if Italy allows flights/visitors from China before the US, that is a political statement, regardless of the sanitary reasons. All this while the world has the most inward looking leaders in a generation. 3/3