There were (and still are) few countries that relied completely, or nearly completely, on local manufacturing. It did not work out well for the USSR. I can attest to that from personal experience. As for North Korea, I can’t say. If anyone has traveled there, please share your experience, especially how the economy is doing.
Just take a look at China for a counter-example.
Put aside any political or social objections you may have to them, and just look at their current economy and industrial base.
And tell me they're not a roaring success by those measures.
Yes, there are problems: there always are, always will be. Economies, especially ones of their size, are horrendously complex and unstable things.
But overall they've taken the good fortune that almost fell into their lap--other countries offshoring their manufacturing onto their shores--and made the most of it.
Just to clarify my argument about economic isolationism. China and the USSR are not comparable. I lived in one and have visited the other for business. China imports industrial equipment, machinery, instruments, technology, IP, consumer goods, food, luxury items, etc. The USSR, by contrast, was almost entirely economically self-reliant.
I’m not denying that Asia (not just China, but also Japan, Southeast Asia, East Asia, South Asia) benefited greatly from the offshoring of manufacturing. But it is also important to understand that offshoring wasn’t some evil scheme forced upon by dictators. It was free trade, in which both sides benefited.
Without offshoring, the average Joe might be making a $75 BBQ grill scraper, but would not be able to afford the BBQ grill itself because he would not have disposable income due to the high cost of locally made essential goods. The economy is incredibly complex, and I won’t get into all the ways Joe not being able to buy a BBQ grill could affect Jane, who works at the company that manufactures the grills.
And a final note: In a free market economy, there is one sure way to bring all manufacturing back from relatively poor countries to the US - make the US as poor as the average Asian country. There is also another way: abandon the free market altogether - see my earlier comments about the USSR and North Korea.