On Monday, Chinese vice-premier Wu Yi was too busy with “important and urgent official business” to attend a meeting in Tokyo with Junichiro Koizumi, the Japanese prime minister, that was billed as an opportunity to rebuild fractured ties between Asia's biggest economic powers.

The next day, however, Mme Wu had no difficulty finding time for an official visit to sparsely populated Mongolia, a steppe-land nation that has been enjoying relatively placid relations with China.