Countries dont attack each other like fools, except Iraq case which was more of Bush adamancy.
Compare the level of technology of US defense equipment versus Chinese. US has at least 2 generation ahead fighters, submarines, ICBMs, as well as missile defense systems. The only country that has equivalent power is Russia.
China is inferior power and they know it. Besides US dont have any plausible reason nor does China to attach each other and loose over $1000 billion worth of two way trade.