Can't we start doing regular seismic readings for underground tunnels on the border? Also, if we find these tunnels, we should use our experimental bunker buster bombs on them. We can then see where the tunnels lead to on the other side of the border.
"we should use our experimental bunker buster bombs on them. We can then see where the tunnels lead to on the other side of the border."
Without advertising it, plant land mines in the tunnels and when the illegals or smugglers set them off it collapses the tunnel and eliminates the perpetrators.
"Can't we start doing regular seismic readings for underground tunnels on the border?"
About 1 kiloton be enough?