It’s 40 years since Deng Xiaoping began to open up China to the world and, in doing so, kicked off the enormous growth spurt that has made it a superpower and the globe’s second largest economy. Chinese president Xi Jinping is keenly aware of the symbolism as he takes the stage at the Bo’ao Forum tomorrow, Asia’s Davos.

Every word he says will be keenly watched in Washington DC, where Donald Trump recently predicted that China would dismantle its trade barriers “because it’s the right thing to do”. Xi has allowed expectations to build that he will announce a major new stage in China’s opening up, giving foreign firms better access in services sectors like telecoms, health and education. If he...