Vetfag here and I’ve been mulling what’s been going on.
In about a weeks time they have mobilized 25,000 troops and erected a fence around a very large area of DC, including the Capitol and surrounding area.
The sheer amount of logistics to pull this off and have the infrastructure in place, as well as the supplies needed, this was not thrown together in the last week. The miles of barricade fencing that just happened to be available on such short notice, etc.
It takes months of planning to pull off something of this size and magnitude. This was all planned for in advance.
It's the military, they have prepo stock.
No way the military keeps that amount of fencing in stock. They would have a list of places to buy stuff like that, and perhaps deals on taking priority if/when they need it, but buying and storing that takes money up front, and costs to store.
Plus - how long can something like no-scale fencing be stored before use without degrading, whether some sort of corrosion, settling in odd patterns due to being stacked flat, or something similar? If they need something to count on for security the military is not going to take a chance on something that has been sitting in a warehouse somewhere for years.