China's own debt problem.

[Beebs]

Just in case some people were starting to think that a centrally controlled economy is the wave of the future, and that China is an unstoppable world superpower in waiting.

China Downplays Local Government Debt Risks, Looks at Bond-Sale Mechanism - Bloomberg

http://www.bloomberg.com/news/2011-0...een-toxic.html

Here Comes Swan’s Black Swans – Chinese Bad Debt “Bigger Than Stated” Barnaby Is Right

Chinese public debt: Coming clean | The Economist

Essentially the issue is that the national government has been proving huge "loans" to local government, which many local governments won't be able to pay, and then the national government rolls it over and loans again.

That is a very short and simple version of it, but the main point is that this, along with things like an aging population, shows that the prevalent view that 'we are all going to be speaking Chinese soon" are not nearly as close to correct as most people think.