What are the main problems that may arise if all countries close (or almost close) their borders for 1-2 years or more?
Fortunately, it cannot be said that some kind of isolation is felt now, because we can easily call (Skype) a person who lives in another country.
But what problems can arise?
Main problem here are the people who are working abroad as their main source of income. If they cannot go back to their work abroad, then that's going to be a big big issue.