You have touched on something that just doesn't get much notice by the money pundits. When US companies move off shore,
I'll bet much of the profits do come back to the U.S.
" Already, the U.S. has to import $1.8 billion in foreign savings every day to pay for our appetite for imported goods. "
Now, I'm sure that's changed some. But how much? How advanced, technically is China now? They are buying tanks and missiles from Russia that are 25 years old. Yeah, they got "advanced" stuff from Hughes in the 1990s (not since) meaning that at best their stuff is 10 years behind ours. Proprietary stuff, like computers and so forth, is likely 30 years behind ours.
But say it is within five years: the nature of closed or quasi-closed societies is that ideas do NOT percolate. Very quickly, "cutting edge" technology becomes obsolete. I am extremely skeptical about "threats" from societies like China, or even Japan. We saw how quickly the Japanese "threat" unraveled.