Jay Tee Hsu, head of semiconductors and materials at the Boston Consulting Group, said even the goal of achieving 70%-80% self-sufficiency is "extremely difficult." ... It can be extremely difficult for any country or region to secure all the fronts."

"It's not just the factories that make the chips, but everything that goes into it," said Jens Liebermann, head of global business management for semiconductors and electronic materials at BASF, the German chemical group. "All materials, chemicals, gases and raw materials for them. Everything must be in place. It all comes down to where is the source, where is the raw material, where is the production, and who can handle the logistics?"

Morris Chang, a semiconductor industry elder who founded and previously led TSMC, was most forthright in his US address.

"If you want to rebuild the full US semiconductor supply chain, you can't do that," he told an industry forum last year. "Even after you spend hundreds of billions of dollars, you will still find that the supply chain is incomplete, and you will find that it will be very costly, much more expensive than what you have now."