In the Oval Office on Thursday, Donald Trump made a joke about Pearl Harbour to the Japanese prime minister's face. It lasted seconds. It undid decades.
Sanae Takaichi had come to Washington having done everything the moment required. She had flown from Tokyo, taken her seat in the Oval Office, and told Donald Trump she believed he was the only person on earth capable of achieving world peace. She had previously offered to nominate him for the Nobel Prize. The meeting was, by all accounts, congenial, shaped by careful flattery, patient diplomacy, and the management of a bilateral relationship that matters enormously to Japan and that, under this president, requires a certain amount of performance alongside the substance.
