Well the problem with that is they wouldnt have time to "go nuclear".If we invaded they would be overthrown in a matter of weeks,
Bwahahahah

, invade China? Even if in the wildest dreams of psycotic generals would it happen without some serious prep work of population reduction before hand.
For another thing, how are they not going to have time when it would take at least months maybe years to build up a force large enough to attempt to move on China, its not like you can keep that secret or anything. You do know China is nuclear capable right now right?
We have not employed an overwhelming assault anywhere without owning the air since the middle of WW2 , the air battle of China alone would last years.
Frankly, the idea of invasion from either, on either is pure fantasy. It may be more plausible that we meet on some contested ground, possiblely Taiwan, but even then I have doubts that we would have boots on the ground there, it would be a standoff fight from start to finish.
Also dont underestimate special forces of any country. Just becasue they are not glorified, doesnt mean they are not a threat.