So, how long before there is another facility elsewhere that can do the validation? It'll presumably be wrapped up as a Softbank subsidiary, in Delaware no doubt, with no direct connection to ARM so that plausible deniability is possible.
But at some point there could be a real risk of the US cutting itself off from technological developments elsehwere in the world. Presumably meaning it would have to resort to stealing technology like it did routinely in the 19th century. Oh, the irony.