China? Nuke the US.. their biggest paycheck evar? LOL!
China is being run by guys who are quite happy with the status quo.. why nuke us when in 30 years they'll just own us outright?
The US? Threaten to go to the Nuclear mat over Taiwan? With a formal US policy that calls for One China and stresses that peaceful reapprochment is the only accpetable means for reunification? Fact is, the US would regard hostile action towards Taiwan as a 'matter of grave concern'.
Folks.. a 'clue' here.. The loss of South Vietnam was a 'matter of grave concern'. How on earth could anybody get 'we'll nuke yer goofy little butts back into the stone age if you invade Taiwan' outta 'matter of grave concern'?
More likely, we'd move into the Straights with a coupla carrier groups like we did during the last crisis and make it clear that we'd up our F-16 and and F-15 deliveries to Taiwan if they didn't go back to 'playing nice' with their rebelious democratic province.
Damn.. you guys are reading too many Tom Clancy franchise novels.

The Chinese won't attack the US.. would piss off too many customers.