It was alright, but..
I'm not sure that you know that China has an alliance with other countries as well. China doesn't attack America because we have an alliance, America doesn't attack China for the same reason. Unless China's attack on America was random and thoughtless (something China has never done in their history at all), they would have brought allied forces with them. Yes, America has done such things (hell, we're doing one now.. Iraq..), but China tends to get their whole alliance on their side before they attack. That would have had a completely different outcome entirely.