For the better part of three years—1,016 days to be exact—China will have been closed to the world. Most foreign students left the country at the start of the pandemic. Tourists have stopped visiting. Chinese scientists have stopped attending foreign conferences. Expat executives were barred from returning to their businesses in China. So when the country opens its borders on January 8th, abandoning the last remnants of its “zero-covid” policy, the renewal of commercial, intellectual and cultural contact will have huge consequences, mostly benign.