Uh-huh. And one that costs $10 to do that is 100 times as effective as one that costs $1,000.
Smart bombs are effective because their cost is low relative to the value of the targets they destroy.
One more time: what features do you expect to see on landmines to make them 100 times as effective in return for a 100-fold increase in price?
Let's build the wall and put the troops on it first, maybe we won't even need landmines. It might be overkill.