THAT China has lifted so many out of poverty and become so powerful so quickly is remarkable. No less remarkable is how America, the incumbent superpower, has mostly treated China’s rise less as a threat than an opportunity. However, in the South China Sea, through which about 30% of the world’s trade passes, China risks jeopardising this benign arrangement. Its behaviour there disdains international law, scares its neighbours and heightens the danger of conflict with some of them and with America itself. Recalling its own slogans about stability and peace, it should back off.