There is a dangerous chill developing in the relationship between the US and China. The temperature has dropped further with the withdrawal of Steven Spielberg, the American film director, as an artistic adviser to the 2008 Olympic Games in Beijing because of China’s failure to do more to curb gross human rights abuses in Sudan.

A day earlier, the US announced a series of arrests over alleged spying by China. Mr Spielberg’s decision, like the arrests, underlines US concerns about China’s increasing military, diplomatic and commercial influence in the world.