Just after the ride-hailing giant made a splashy stockmarket debut, Chinese regulators came down hard. Why is the country crimping its tech champions? There is something missing at many American embassies around the world: American ambassadors. We ask why so few are in post, and what risk that poses. And the not-so-simple task of counting the Earth’s oceans.

For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer