Heck, a free marketer would want the mines open and operating here . . . why can't a protectionist act the same way?
Actually the Chicoms gamed the "system" that you are defending, and by dumping magnetic product, with misappropriated (stolen intellectual property) technology without which they could not have competed. They dumped so much product on the "market" they severely depressed it, such that it was effective in "persuading" Unocal to shut down, creating a defacto Chinese monopoly of a strategic supply. Unocal did this out of simple economics (they couldn't beat the Chinese Treasury and slave labor force) and also because they had no certain victory in an uphill fight against the Chicom's left hands...their American stooges masquerading as simple enviro fanatics.
It was not coincidence.
"Once is Happenstance. Twice is Coincidence. The third time it's Enemy action".
And it is a loss of industrial capacity that could have profound implications in a direct clash. Restarting an operation such as that is not like pushing a switch. And by your phoney free trade fanatacism, you are doing the enemy's work by keeping America misinformed, disinformed, and blinded with confusion. Keeping the public in the dark about how it is being stripped of its means of defense.