Do you remember the most recent war with Iraq? We had depleted our inventory of cruise missiles and JDAMs almost completely after taking care of Afghanistan. These were the precision weapons critical to our military. We relied on a tiny Swiss company for an oscillating crystal (the strobe) for the electronics. Pretty basic technology. We invented it. And we used to make almost all of them right here. Not super-cutting-edge technology anymore. It became classified 'mature technology'. For analogy's sake, let's call the strobe a 'Nail'. We had allowed our semi-conductor manufacturers of strobe chips to go out of business and be bought up by foreigners, and their technology transferred, sold off-- outsourced to Asia and Europe, BTW.
So the Swiss company wound up being the supplying vendor for a chip no longer made in the U.S. There were no fabrications operations anywhere in the U.S. that COULD make them anymore.
Then the Swiss government, running with the French Anti-American tide...banned shipments of the crystal to their 'ally' the U.S. way back in 2001 as they protested our finishing the war against terror-sponsors. Fortunately, there were still a few people who remembered how to set up a factory from scratch again and churn out several thousand such chips. But they literally, from blank-check go-ahead at the beginning of 2002, to the end of October, 2002, had to have a crash program to get this one plant up and running. These chips, as a result, cost ten times what the 'global' market for them would have been. And it wasn't until October that we had any chips. A lot of ordnance had to be rebuilt very inefficiently awaiting the missing 'nail' which meant we had no 'shoes' or 'horses' for the war until very late. This re-armament effort was the reason we waited almost 14 months from the Afghan war's conclusion to go after Osama's biggest covert sponsor (or 'hiring agent').
This was an indusrial capability which, in a limited way, was reconstituted at great expense...but it took longer than 'a few months'. And many other industries which are being sucked into the Chinese black hole will be vastly more difficult to reconstitute. The Neodymium super-magnets for example. Also critical to the JDAMs, the F-16's, Pratt & Whitney's best engines, all our aeronautical servo-motors, etc... If China cuts us off, (they bought GM's highly profitable Magnequench division which invented them) and relocated it to Tianjin, lock stock and barrel...we're simply SOL.