You are focusing too much on the war aspect instead of what happens at home.
What happens to companies like Apple and nVidia when for whatever reason they can no longer manufacture in China. Apple luckily has a rainy day fund to fund itself until heat death of the universe, but other companies may not be so lucky.
I’m sure it would take decades at this point to develop the talent, infrastructure and scale in manufacturing that China currently has
Sure, the US military has maintained low-volume domestic manufacturing capability in those areas to meet peacetime military demand.
However, you mentioned WWII. Did the US fight that with just its preexisting military-allocated production capacity? It did not. You had jukebox companies drafted into making rifles and car companies into building tanks and airplanes. Electronics are key to most modern military equipment, and guess who has the spare manufacturing capacity in that area now?
> Also, ICBMs fly both ways. But while nobody decides to press the "End Game" button, the US with its self sufficient continent can weather more punches than any other country in any conceivable conventional war scenario.
Attacks with long-range conventional missiles are also a distinct possibility.
You also used that word "self-sufficient" again. The issue here is contemporary Western politico-economic dogma has abandoned the idea of self-sufficiency in favor of interdependence and free trade. China, has not done that, and appears to have deliberate industrial policy with the goal of modernized self-sufficiency. IIRC, its main imports are raw materials, which it may still be able to obtain through trade (e.g. Russian oil and gas) or military capture in a hot war.
Furthermore for all the Chinese efforts for self sufficiency, it lacks that in high tech manufacturing.
Also, ICBMs fly both ways. But while nobody decides to press the "End Game" button, the US with its self sufficient continent can weather more punches than any other country in any conceivable conventional war scenario.