When one studies the runup towards World War II the appeasement of Germany plays an important part. It was not just Munich 1938: on many prior ocassions (like the remilitarisation of the Rhineland) Germany had imposed its will with fait accompli's and military threats. In many cases Germany was just ondoing unfair provisions of the Versailles Treaty. Yet the effect was the same: Germany became used to getting its way unilaterally and became overconfident.
In China we see now a similar pattern. Everybody knows that China will have to do something about its trade surplus and its undervalued renminbi. Yet Obama (just as Bush before him) are too timid to say it openly. Instead they let themselves be lectured again and again by arrogant Chinese leaders. At the end of his last visit to China Obama even signed a common declaration that was widely seen a kowtowing to China's ambitions for regional hegomony.
The price of this indulgence is becoming higher and higher. The world economy is getting seriously out of balance and may end up in a crisis. China's leaders become more and more bold in their demands. Their recent noise about the Dalai Lama's visit to the Tamang region in India was the most striking example. And when one reads posts by Chinese on the internet it becomes clear that the problem is much wider. Many of them are extremely nationalist and quite a few threaten with war if China doesn't get its way.
One can only hope that it doesn't take too long before mr. Obama finally realizes that he can keep giving in to China forever because it will only lead to a steady increase of their demands. And this concerns not only the US: Other countries face the same problem with China.