Good reflection by Arturo Pérez-Reverte on the fall or the roman empire and current Europe. I don't necessarily aggree with everything he says, but it is a good topic for discussion.
Same issues apply with the US southern border.
If you don't read spanish, try a good online translator. I'm sure there is an english version somewhere, but could not find it.
http://www.lanacion.com.ar/1828991-l...mperio-vencido