Over fifty years ago, when I was training at the U.S. Army Engineer center, we actually had a section of training, as I recall known as “Field Forts”, where we were exposed to the principles of constructing trenches and dugouts, as if the army was going to fight another war like the Western Front, which at the time was fifty years (and three subsequent wars) in the past. This isn’t as surprising as it sounds, though; in Basic Training we were instructed in the “art” of bayonet fighting, even though the little bayonet for the M-16 rifle was mostly good for opening C-Ration cans.