What about them? Who cares if they stay home? We should not be educating our enemies in the first place and business does not require travel as Amazon proves. Education does not require presence either as far as that goes.
No country can survive the erasure of their borders.
Foreign tourists contribute hundreds of millions of dollars a year to the economy. End that and you're going to lose tens of thousands of jobs and quite a bit of tax revenue. No country can survive the erasure of their borders.
Nobody is talking about erasing borders. But you want to make them impenetrable to everyone from outside the country. That doesn't help our survival either.