Nearly all state borders in the world are arbitrary and purely political constructs. Also, by definition, they are temporary and provisional. Even in my lifetime, I have seen state borders appear, disappear, appear again, and change.
The fact is that most state borders do not really 'exist' - and the funny thing is that by our imagined need to build border walls, we are proving the very fact of a border's non- existence.
The idea of proving the non-existence of something by building something to mark the illusion of its existence might be 'funny' - but all fun disappears when we consider the immense amount of missed opportunities, suffering and misery that this has been causing to mankind.