Nothing will perfectly secure a border of that length, not even a minefield. https://en.wikipedia.org/wiki/Fortifications_of_the_inner_German_border https://en

Nothing will perfectly secure a border of that length, not even a minefield. https://en.wikipedia.org/wiki/Fortifications_of_the_inner_German_border https://en.wikipedia.org/wiki/Fortifications_of_the_inner_Ge...