LONDON — The idea of "Chimerica" was always too good to be true, but the rapidity with which Sino-U.S. ties have unraveled over the past few months has even surprised those who were cynical about Barack Obama's overtures to China to begin with.

The state of Sino-U.S. ties is so pitiful these days that even as the Chinese commerce minister openly warns the United States that it will suffer consequences if it levies punitive tariffs on Chinese imports, Chinese military leaders are contemplating the possibility of an eventual, all-out war with the U.S. over the status of global superpower.

The West, meanwhile, is souring on China. Gone is the talk of China as a responsible stakeholder in the international system. Instead, Google's withdrawal from China following a high-profile public spat is seen as symptomatic of the problems that China's rise generates for Western global norms. China's undervalued renminbi, for example, is no longer considered a trade problem solely for the U.S.