China's mindblowing reaction towards US treasury debt

It was believed that after the financial crisis, China will reduce its reserves in US treasury for financing their debt from this source. They started reducing their reserves in November 2008 when the US treasury yield was less than 3% but they started to buy a huge amount again when the yield started going up to 3%. So from July 2009, the China's demand for US treasury has started picking up again.

Why China's economy is trusting more on US when everything has proved to fatal in this crisis? This is an important question to look out for in future.