Ha! so we are more or less in agreement.
Except......
No one can predict how a conflict will escalate...no one.
In the civil war they thought it would be over very quickly, 3 months max.
In WWI, there was a serious argument made that Europe was so closely economically intertwined the various powers could not fight a long war...but they did.
It is quite possible we try a show of force with China or the other way around and it escalates beyond the point where either side can back down. it is a matter of face. Chinese honor is bound up with Face, perhaps less than the Japanese but not all that much less.
Were such a situation to come to pass, we are in no way prepared to fight such a war, as you seem to be aware.
So, wadda ya think about my proposed supporting cast?