Uh, trading? Immigrants? WAR?
There are a lot of reasons why america should concern itself with wath China is doing, like...
The Recycling Shortage (thingy) - China put stricter guidelines for other country's waste that they deposit to China.
Immigrants - Wonder why (maybe all) major cities has a China Town? Yeah, immigrants.
More people = Economy goes up
More tourists = Cash
War - Maybe not today, but in the past, people were concerned if China was gonna start a World War.