The inability of the US/NATO to prevent Russia from annexing the Crimea and to sustain operations by the DNR in Eastern Ukraine is extremely telling.
Chinahas no illusions about the real power of the Russian military and state. So when Putin was able to win his staring contest against Obama in Ukraine, jaws dropped in China, and people began to reconsider some preconceived notions regarding the supposed absolute authority of the US.
For decades, China has held the belief that if it can play it's cards right, the proper combination of economic strength and target military developments can end US strategic dominance in the Western Pacific. Now that goal looks more and more within reach as the strength of American power projection is called into question.