Borders are a more modern concept anyway, and even modern borders are anything but a line on a map. (Consider airports. Embassies. Checkpoints. Federal agencies

Borders are a more modern concept anyway, and even modern borders are anything but a line on a map. (Consider airports. Embassies. Checkpoints. Federal agencies operating inside neighboring countries to deter migration. Etc) Boundaries are policies, not objects. They always have been.