Obstacles, in order to be effective, need overwatch. Otherwise they’re annoying speed bumps.
Imagine stringing concertina wire across a road. Triple-strand, reinforced with pickets—the works. Now, everyone pulls back due to...I don’t know, budget cuts. When the enemy infantry hits the wire obstacle, what happens? Nothing. They break out their wire cutting tools, reduce it and move on. It added a few minutes to their trip, but that’s it.
Now instead of pulling back, imagine placing an Infantry platoon with its machine gun teams and M203s and frags and whatever else in prepared positions overlooking the wire obstacle. What happens to the enemy infantry?
I agree that a wall can help canalize the illegals, but unless follow-on admins commit to the necessary personnel to man the thing, it’s not going to do a whole lot of good. A wall is certainly better than no wall, but too many keep talking like a wall is THE solution rather than a part of one.
Imagine stringing concertina wire across a road. Triple-strand, reinforced with pickets—the works. Now, everyone pulls back due to...I don’t know, budget cuts. When the enemy infantry hits the wire obstacle, what happens? Nothing. They break out their wire cutting tools, reduce it and move on. It added a few minutes to their trip, but that’s it.