Charlie Self wrote:

It was our manufacturing
capacity, the awakening of a sleeping giant, that won World War II.
If we couldn't have supplied our soliders and most of those of the
rest of what came to be known as the free world, we lost. We did it.
Or, rather, our parents and grandparents did it. I don't think we
can.

My understanding (which could be wrong) is the U.S. lacks many of the
necessary quantities of raw materials (like oil and many metals) for
extended self-sustained manufacturing anyway.

-- Mark