There will always be borders, just as a person's skin is a border to his body.
People need to socialize together to some extent. But they never socialize entirely. If they did, they would combine with those with whom they socialize.
Borders are good, just like differences of opinion are good. But crossing borders under invitation or contract (visa) is good just like sharing opinions is good.
In the world today we need borders, I agree, but I believe that time will come when we will not need borders.
Believers waiting for ''a New Jerusalem'' ideal world governed by God.
Communist also belived in ideal world, communist world, Atheists believe in utopia etc.
They all believe in great social change after which people will live in an ideal world without division or conflict.
I'm not optimistic that such great social changes will happen soon but it will happen.
People always want to live better and more freely and it will never change.