The only way you can cost effectively bring back manufacturing is automation. This still means less labor hour per dollar of products produced. This is the trend of human civilization since stone age. I don't think it is all bad, when the economy is moving back domestically. What I have problem with is the unrealistic expectation that moving production back to the US "will create jobs". It may create some, it may also lose some, we will find out very soon how it goes.
A lot of today's manufacturing work is white collar support role for the automation. Those are service jobs that even if production is outsourced or offshored they remains with the US. I would say most of the work in semiconductor is white collar for the obvious reason (you don't want human in cleanroom). Automotive will be like that more and more and this is why union is dying, not because they siphon money off vs foreign labor unions.
The biggest obstacle to US production is the accountant CEO without an engineering degree, chasing quarter earning and tanking companies over 10 years.
Most US debts are issued with USD so in the worst case we can issue more bonds or print more money. This is not something 3rd world country can do so they have things like 20% inflation and devaluation of 50%. Foreign debt holders can hedge their currency to USD but that risk having their inflation being much larger than US due to economy size difference, or forced to increase interest rate when they should have drop them, causing their own economical problem.
The way I see it we can slowly inflate away our debt, or we can have a sudden shock to drop it, pick your poison.
