The previous poster was saying something else - you'd need a population wedded to that idea, because a tiny fraction of the population can volunteer, yes, but cannot produce the funds, and the enormous work involved in building, launching, assembling in orbit, and sending these ships on their way...

And it really would be a great effort, unless spaceflight becomes dirt cheap and simple, in which case yes, a small group of people could just put everything together and fly off.

"But now the US is finally telling China that enough is enough, and that it can't expect to wantonly proliferate nuclear weapons technology without facing consequences."

Consequences like having to endure *very* stern looks, and, in extreme cases, a very carefully worded warning.

Let's be serious for a second - short of full-scale war, there's nothing the US could to do make China do something or stop doing something, if they really don't wanna.
They're a bit too big to respond to normal intimidation, and economic sanctions would hurt the US at least as bad as China, considering the ties between these countries.