Just the other day here on HN I read an account from a founder who did just that- in early 2008. He ended up having a warehouse full of raw materials and no cash to make payroll. That's one way a business dies.
So, this talking point sounds good, those damn MBAs and their JITs!, but carries its own set of risks. It's important for each business to balance those risks and arrive at their own decision. It's not as cut-and-dry as one would necessarily think.
Buy stuff and sit on it for half it's shelf life, and when it's done sell it at just a little bit under fair market cost.
E.G. Buy N95 masks with a 5 year shelf life, hold them for 2, and rotate it out of the warehouse so the warehouse always has newer stuff and places that use it like construction and hospitals have a price stabilized source.
We could definitely retool our regulatory policy if we want to improve our posture in the trade conflict.
JIT is about freeing up capital (which in the 80s when JIT came in was expensive). It also reduces waste a lot.
Then hold that inventory in Canada or Mexico or India or China? This isn't a hard problem.
You have a warehouse that stores stuff, and sells it to manufacturers when JIT runs into issues.
The MBAs running US manufacturers need to scrap their JIT strategies, build some warehouses, and start keeping a store of the essentials. If a tangible good is essential to your business continuity on a 6 or 12 month horizon, then your business should not outsource the maintenance of this lifeline, regardless of whether your supplier is domestic.