China thinks long term so why worry about small short term issues, just stop buying US debt and a problem starts very quickly.
China offloaded significant amount of Debt in December 13 and could do easily again.
http://www.treasury.gov/resource-cen...uments/mfh.txt
As for Taiwan, China always viewed it as a province which broke out without agreement of rest of the nation, funnily enough this is the view being spouted about Crimea by the west.
China will quite happily turn this on the west stating that West must support it in its claim for reunification.
Would US sacrifice a foreign country rather than get embroiled in a nuclear exchange that could destroy one of its cities ........... I must admit to making a guess but that is a rational guess, not sure that rationality applies with buckets of instant sunshine.