Worse than the sell-off of the equipment and technologies is the diminished workforce with the skills to operate and produce what we need. Five will get you ten that most people don’t even know a tool and die maker.
When a one factory town loses it’s factory, the whole thing closes down like a gold rush mining town in the 1800’s.
And that to me is even worse than the loss of machinery.
The machines are not all that hard to build if you have the blueprints, a decent transportation infrastructure, and enough people who at least have a fair idea how to build and maintain them. (experience beats ‘book smarts’ a lot in that particular field) To destroy our manufacturing capacity in, say, the 1950’s you’d have had to literally level us back to the stone age.
But if you have a massive lack of qualified personnel as America does now...you are in a sore spot indeed if the imports suddenly go away. To reword an old saying “Machines may not make more skilled workers, but skilled workers can always make you more machines.”