This is just the same sort of paranoia that used to exist about Russia.
Quite aside from not having the means to mount any sort of invasion, quite aside from that being such a ludicrous thing to attempt against a major country in the world today, and quite aside from the fact that it is a mistake to think of China as some single unified entitiy moving with one voice towards one goal...
... Ya is bang on the money when he mentions that China simply has no interest in upsetting the much more viable way of being powerful- economy.
There seems to be this vibe to fear China these days. But it just seems that the US, as ever, doesn't want any other powerful traders in the world, as evidenced by their protecionist policies and equal worry about Europe.
The idea that China is going to beomce a post-modern Communist/evil superpower is absurd. By opening up to market forces, they will eventualy become like all other free market countries.
Though some might say that having two Americas in the world is hardly a good thing, it's still not the situation people often make it out to be.