What will the United States do when China attacks Japan?

I can't tell who is stupider-China or Obama's US. If the US and China went to war, all debt owed China would be gone-instantly. It would be the biggest financial hoodwink in history. The question is not what America dares to do-it is what China dares to do. If China pulls off some crap, they will find themselves out an awful lot of money. If they do not realize that, they are stupid.