Push comes closer to shove

Taiwan/China: China has dropped a mini “T-bomb”. For four decades, Taiwan has been the focus of an awkward stand-off between Washington and Beijing. Now China's foreign ministry has threatened to sanction American firms that take part in a proposed $6.4 billion sale of weapons to the island. Chutzpah befits a growing superpower, but China may have overplayed its hand.

Beijing claims sovereignty over Taiwan, but the United States has historically taken a cooler view. A 1979 act obliges the United States to help the democratically governed island defend itself, and stalemate has mostly prevailed. Missile tests by Beijing invoked an angry US response in the mid-nineties. Beijing pulled military co-operation in a fit of pique in 2008, but softened six months later.

This conflict is more serious, especially as nerves are already strained between Washington and its number-two trade partner. The US government is backing search giant Google in a row over cyber-hacking and free speech. China managed to make the United States look impotent at the Copenhagen climate-change talks. Then there is the huge financial imbalance: China owns, while the United States mostly owes.

Fireworks over Taiwan could spill over into trade conflict — something Google's gripes have not. Beijing has targeted individual companies, including Boeing , Lockheed Martin and United Technologies. All are big employers in the United States. Boeing has designs on a market it estimates is worth $400 billion. If China carries through on threats, unions, and voters, may well call for protectionist revenge.

For China, the point hardly looks worth a fight. A few more missiles would not help Taiwan to fend off a full-scale military attack from China. And the island government, under president Ma Ying-Jeou, is basically moving in a Beijing-friendly direction already.

One day the People’s Republic will be rich and strong enough to tell America what to do, but that day has not arrived. Exports remain a pillar of the economy, and more go to the United States than any other country. While a manufacturing survey released on Monday showed healthy new orders, China is not yet on a firm enough footing to withstand a round of punitive tariffs. For the adolescent superpower, trade still beats triumphalism.