Patrol with drones and cameras
Obama pulled down the cameras that Bush had put up, claiming that they were ineffective because they couldn’t distinguish between animals and man. Seems to me that software could do that now, but even if not, a person looking at the camera feed when an alert is issued could certainly do that.
Yes I agree with all of this but people still need to patrol & interdict or you end up saying like the last Roman commander at Hadrian’s Wall, “Where did all these Picts come from?”.
The last Han commander on the Great Wall was not available for comment because his head was stuck on a Nongol lance!