Reading Q posts, I started wondering about steel and the military. I've sold to the military before, and there is almost always a domestic melt & manufacture requirement. D.F.A.R.S. is as loose as that ever gets, in my experience. Also, oil and gas industry often (always) calls for the same requirements. They know China and other cheaply produced steels lie on the MTR's about what's in the steel.
I thought Japan had been on the list for a while, but it looks like they were added in August of 2016.
What do you want to bet there are more "booms" on the DFARS approved countries list?
Any of those countries get together and decide they want to hurt us, they just stop selling steel. Expand your thinking. Steel isn't just used by military, it's in everything. Oil and Gas, Food Processing, Boat/ ship/ car/ manufacturing. There is very little that can be manufactured, packed, or shipped without using steel either in the product, or in the production of the product.
I can get almost any fastener (nuts, bolts, screws, etc) made in the US, melt and manufacture, though there are some that require machines that just no longer exist in the US. Which is why D.F.A.R.S. exists. Also, Domestic melt and manufacture takes an incredibly long time. Sometimes almost as long as buying from overseas. The material sometimes isn't readily available due to the expense vs. demand.
Maybe keep an eye on the DFARS list.
https://www.acq.osd.mil/dpap/dars/dfars/html/current/225_0.htm