What do they have in common?
It seems as though the border wall has been dominating in our national conversation for 3-4 years, in one way or another. Before the 2016 presidential election and ever since. Wall this, wall that, concrete, steel, concertina wire, etc.
I've been thinking about this for a long time and thought I'd briefly share my observations about "the wall" and the similarities to a military minefield — being an ex-infantryman.
Here is the deal. A minefield is pretty much worthless as a barrier and as an obstacle if it is not "covered by observation and fire." Minefields can be cleared. It may take a bit of time, but with enough people and tools, they merely slow the enemy down. Observation and fire mean, visual observation, eyes on the target, watching for any movement by the enemy to breach the minefield. Fire means direct, rifle or machine gun fire that can sweep the minefield, engaging any persons trying to clear the minefield. It could also include "indirect fire" from mortars or artillery. Although that is not a preferred option since the impacts from those rounds will destroy mines within the field. But, you can attack forces who are approaching the minefield up to 11 miles out with conventional artillery.
So it is with any wall, made of any material. You must have observation/detection of anyone trying to penetrate the wall, by going through it, over it or under it. For the purposes of the border wall, we are not going to engage people trying to enter the United States with rifles, machine guns or artillery. But you do need resources in the form of response personnel who can come to the area where there is an "intrusion" and respond accordingly.
Here then is the catch. We don't have the technology or people to perform the "observation role" for a 2,000-mile border and the number of staff to respond to people entering illegally is not there either. It has already been admitted that a wall is not a practical technique for areas of mountainous terrain that forms a natural barrier.
I'll leave you with one last military factoid. If the enemy you are attacking thinks that they have a natural barrier that will prevent enemy forces from attacking from one specific direction, then just refer to the Second Punic War and Hannibal going through the Alps with elephants to surprise the Romans. Motivated people will always find a way to get around "a wall/barrier."
We could spend what should be scarce tax dollars for other purposes. How about climate change or, failing that, climate adaptation!