In any economy, no matter how strong and how well-managed, there would be periods of boom and gloom. The US economy is not performing very fine, yet it doesn't mean the country would collapse. This is also true of China. No economy can continue to grow year after year or quarter after quarter - there'll be some slowing down, before new recovery. We don't need to create false alarms. Man countries are far worse than China and USA and they still survive.