there is a literal energetic meaning to borders and frontiers and barriers IN GENERAL

from mitochondrial gradients pushing ions through a hole to make a protein complex spin so to chain double phosphate groups in ADP molecules into triple ATP molecules thereby storing energy.

all the way up to an international entities controlling flows of goods and people across borders with the goal of maximizing corporate and government profits (storing/collecting energy)

i.e. utilizing the energetic gradient caused by citizens and people and families trying to meet each other across the border including sending each other goods, flavors, candies, etcs