It hasn't been a banner few weeks for U.S.-China relations. In mid-January, Google announced that it was contemplating pulling out of China because of repeated attacks on its network as well as censorship constraints. In the past week, the U.S. government authorized $6 billion in arms sales to Taiwan, and the White House announced that President Obama would meet with the Dalai Lama after having postponed that visit last fall on the eve of Obama's trip to China.

Beijing's response has been increasingly unfriendly, even hostile. A senior Communist Party official announced that any meeting between the President and Tibet's spiritual leader would "seriously undermine the political foundation of Sino-U.S. relations" and would lead to "corresponding action" - a phrase made more ominous by its utter vagueness. Then, in response to the proposed Taiwan arms sales, the Chinese threatened sanctions against U.S. defense companies, which include conglomerates doing substantial nonmilitary business in China such as United Technologies, which has seen booming demand for its Otis elevators in Chinese skyscrapers, and Boeing, which has staked its future growth in part on demand from China's air carriers. Most recently, on Feb. 5, China's Commerce Ministry accused the U.S. of dumping chicken on the China market.

This increasing truculence is a direct reflection of a rapidly shifting economic balance of power. One of the consequences of the financial crisis of 2008-09 was the catapulting of China to the forefront of the global economic system. That trend wasn't created by the crisis, but the crisis certainly accelerated it. As the U.S., Europe and Japan contracted sharply, China registered its own brief, if scary, dip and then proceeded to use its trillions in foreign reserves to undertake a massive spending program. More effective than similar stimulus packages in the United States and elsewhere, the approach by the Chinese government not only halted the swoon but propelled China to even more robust growth.