The Japanese are keeping their fingers crossed that China’s new team under Xi Jinping will try to repair relations, reassured that the new foreign minister spent seven years in Tokyo. But again, as one diplomat cautioned, that may make him even more hawkish to prove his colours.

As `black swans’ go, an outright war between the two great powers of Asia would surely be dramatic, and it could not easily be contained since America is bound by treaties to defend Japan if it is attacked. This includes an attack on the Senkaku islands.

One shudders to think what would happen if China and the US itself came to blows in any form. It would be an earthquake for the global strategic and economic order. The Chinese and US economies are locked together in a sort of `Chimerica’, a single dollar-based trading system. China owns $2 trillion of US debt. Much of the US manufacturing base is in the Pearl River Delta or the lower Yangtse.

Washington is scrupulously neutral over legal claims of sovereignty — an issue that soon gets bogged down in the minutiae of the Potsdam Declaration — but it stands by Japan on the core principle of the post-War order, that international borders may not be changed by force or coercion.