It's only minimal compared to our problems.
http://en.wikipedia.org/wiki/List_of_countries_by_current_account_balance
And China will have problems, particularly their housing market, which will crash, but that will only create buying opportunities in Asia. In the long run, Asia is the future.
The CAB is a far larger problem for China than it is for the US. How else can China keep up the illusion of a manufacturing economy without the positive balance of trade created by an artificial currency peg?
They can't. Just as with the US, the housing market isn't insular and the credit created over there is many times as large as it was here.
Lastly, as a debtor whose creditors have absolutely no recourse to the debtor nation, who owns who? China is effectively an unsecured creditor in the US, beholden to the US to purchase USTs endlessly until China's economy becomes a fully self-sustaining consumerist economy, which it is still a long way from becoming.
China can't force the US to pay. It can't dump the USTs in the open market, otherwise it will destroy its own economy. It can't do anything at all with the USTs.
They are trapped by their own hubris of the "middle kingdom".
You know what I say? Fuck em. QE3 @ 2TR. Fuck em with their manipulation of the world trade supply/demand dynamics. Fuck em with their making the US a mega-creditor nation by leeching our manufacturing. Fuck em for thinking they can bootstrap their economy on the backs of Americans.
Let them eat inflation and see how it feels to be manipulated.