[mtphil]

"Sadly, a considerable number of people in the U.S. are dead set against the wall, and don't understand that the requirement for ladders and climbing makes non-customs crossings more conspicuous and time-consuming, making unpredictable and regular patrols considerably more effective whether or not the wall proves to be a total impasse."

YIKES.

https://mitpress.mit.edu/books/walled-states-waning-sovereig...

[microcolonel]

> Why do walls marking national boundaries proliferate amid widespread proclamations of global connectedness and despite anticipation of a world without borders? Why are barricades built of concrete, steel, and barbed wire when threats to the nation today are so often miniaturized, vaporous, clandestine, dispersed, or networked?

Because some specific threats, specifically to sovereignty, can be deterred, retarded, and/or prevented by a wall.