Sun Tzu would generally frown on handing over your weaknesses to your enemies, don't you think?

Sure. But that statement runs both ways, doesn't it?

China and the rest of the world (ROW) are now mutually dependent. Just like us, China relies on imports for key sectors of their economies - sectors that they are not self-sufficient in. This includes agriculture, energy (they run huge imports of all fossil fuels), and most very advanced technology.

For example, China has gone from being a net oil exporter in the early 1990's to becoming the worlds largest oil importer at about 11 million bpd. Today, the Oil Weapon is pointed squarely at China instead of the U.S. The same is true of food - China's the largest importer of food, and depends on imports for approximately roughly 1/3 of its food supply. Which is good! It makes them far less likely to engage in activities that would blow up the world economy! The consequence of that is that China has also handed over its weaknesses to their enemies.

That was one of the key strategic reason why China was admitted to the WTO and integrated into the global economy - to reduce the chances that we would be likely to be pointing guns at them in the near future.

We, however, need the ability to source certain critical items domestically. One nice thing about being the United States and the system we have is that loads of folks sit around trying to how to make stuff in new fangled ways.

Those two things are not unrelated. As I mentioned in the last post, you can't source "critical items" domestically unless you're willing to make enormous sacrifices in pursuit of that goal. You would need to authorize the federal government to play a much larger role in dictating the economy than it does today. And you would need to divert massive amounts of resources away from more advanced technology and products and into making far simpler stuff.

A big part of the reason why we have loads of folks sitting around trying to make 3-D printed rocket parts is because we don't have loads of folks sitting around trying to make t-shirts and tennis shoes in a country where textile laborers earn more than $20 per hour.

If we were to take seriously a desire for the U.S. to become more self-sufficient sourcing those certain "critical items" domestically, you would see a vastly different economic policy being implemented by the government. Not just different from what the Democrats have done in the past - different from what the GOP and DJT want to do, also. You'd need a federal government that was robustly enough controlling the domestic economy to divert massive amounts of capital investment from where it is most profitable into what is less profitable but provides a public benefit. But that type of system looks far closer to what Bernie Sanders has in mind than either Trump or the moderate wing of the Democratic party...so I don't take seriously any suggestion that it's in the cards any time soon.