I'm not sure that is generally true. I was involved in a project a few years back for the utility industry that involved precision casting of a large steel component with fairly exacting purity requirements. I checked with domestic manufacturers that I knew had made such things in the past. Couldn't find one to do the job. Most didn't even know how to do it anymore. They'd sold out of the businesses and shipped much of their capabilities offshore.
The job ended up being foreign-sourced from Japan. If the sh*t hits the fan I'm not Japan will be around long as a supplier. They're right under the gun of the NK missiles. Reconstituting that capability here would be neither easy or quick.
I had an R&D program a few years back that needed some specialty nuclear materials that used to be made from a company in Oak Ridge. Called them up and found they'd shipped their production facilities to France. I called the French people and they said they could supply the materials fairly quickly, but it might take us two years to get an export license. Basically to import technology we'd developed here but sold out abroad. Since the program had a one-year timeline, the project got canceled for lack of materials. (And, please, spare me the standard FR response of "well, it's your fault you didn't plan ahead", because we did plan ahead, but you can't plan on your own companies selling out to foreign owners).