A wall by itself is no big deal of an obstacle to overcome. All you need is a ladder, a rope, stairs, whatever.
"A wall by itself is no big deal of an obstacle to overcome. All you need is a ladder, a rope, stairs, whatever."
Very much true. A moat reinforcing it on either side would help but that would be extremely costly given that we're talking about the desert. However, the purpose of a barricade is to slow the advance. The wall of course would have to be monitored 24/7 by aerial drones.