That was in the premise of the question. Obviously if you don't have a secure supply chain for all the parts of a jet, you don't have a secure supply chain for a jet.

It’s probably hard to silo a modern weapon system in the way your question supposes, meaning it may not be a good premise.

By that logic, I guess we oughta onshore everything right? Lest there be a forgotten screw that we don't produce.

And yeah, engineering a market economy is hard (read: impossible). That's why it's largely a fool's errand to try to do it comprehensively.

This is a bad faith argument, and I think you know it. There is a wide gulf between “just a few industries” and “everything”. The first is naive and the latter is impractical. My suggestion is we take a targeted stance, where the solution resides in that gulf.

And for what it’s worth, your screw argument belies a poor understanding, especially given your example of a jet. Aerospace parts are notoriously expensive because we want to track and manage the entire supply chain. That’s why an airplane screw can cost $1k, when naive people assume you can just pick up an equivalent part at Home Depot.

But you just said we effectively can't do it for narrow industries.

I’m saying it’s much harder than your original comment insinuates. That jet in your example has tens of thousands of parts and if you want to protect the entire supply chain, it can’t just be a few companies. Many of those suppliers are also not just supporting jet manufacturers. Eg, a company that makes teflon o-rings for the jet likely makes o-rings for dozens of non-aerospace products. Complex machines are not nice, vertically integrated manufacturing ventures in the modern economy.

I am aware of this, but obviously it's much easier (in that it doesn't outright destroy our way of life) to do it in narrow cases than for everything.

Perhaps I’m confused and misreading your previous comments. It seems like on one hand you’re advocating narrow application, while also saying an entire supply chain would need to be protected to have the intended effect. In a modern economy, those two seem in conflict in any complex system. This means the execution is neither easy nor obvious. The only one I can think of where that may apply is nuclear weapons, which is so tightly controlled it’s more of a quasi-government manufacturing endeavor.