WASHINGTON, Sept. 25 -- Donald Trump walked out to meet Xi Jinping on the tarmac at Joint Base Andrews on Wednesday morning, the first American president in six decades to receive a foreign leader at that airfield, a distinction both delegations had rehearsed before anyone landed. The welcome was calculated for a particular kind of image: two powers that have spent eighteen months managing a relationship built on mutual suspicion, staging a ceremony that suggested otherwise.

By early afternoon, Treasury Secretary Scott Bessent had announced the most concrete output the Washington summit would produce. The trade truce between the United States and China, set to expire on November 10, would be extended for two months, running through Janua...