> it is simply impossible to protect against all eventualities.
Of course. No amount of stockpiling will account for a moon-sized asteroid collision.
> JIT is not to blame here.
Kind of. JIT isn't to blame, but the pressures that reward making every level of industry maximize efficiency, such as by using JIT, is. That is the reason for the supply chain crisis.
The market and tax laws pressure companies to optimize for efficiency as much as possible with their supply chains. Another alternative would be to optimize for robustness, but that would naturally be inefficient and would still be unlikely to endure a 100-year catastrophe unless it were completely unable to survive in a competitive market.
That doesn't mean that we need to change anything, necessarily, but it does mean that we have structured our economy to be less resilient than it could be with potentially very little actual upside.
Even so, some supply chains, like food and clean water, really should be robust rather than efficient. Emergency medical supplies, too, should probably be robust rather than efficient. That's why the Obama pandemic plan included warehouses of medical supplies [0] and FEMA stockpiles food and water.
Utility systems, too, should probably favor robustness. Texas has had a horrific year for it's power industry, and it has revealed how a hypercompetitive marketplace doesn't really serve the public best interest.
Consider civil engineering. We could optimize that for efficiency. That would result in a lot more bridge collapses, structure failures, and so on. Instead, we generally try to overbuild when failure would cause injury or death. The same is true in most engineering contexts. In many cases, industry simply doesn't design for robustness until they are held liable for failures. Notice the rise in corporate insurance rates after computer security audits due to the risk of data loss, and the sudden panic of executives to suddenly have secure systems where before they were more than happy to have databases of plain text passwords and so on.
There are alternatives to profit-motivated business efficiency. We have simply chosen not to do that sort of by accident.
[0]: https://www.npr.org/sections/health-shots/2016/06/27/4830698...