Most periods between the election of a new US president and the inauguration are relatively quiet, with a bustle of appointment-related activity going on behind the scenes but a lack of hostages to fortune given in public.

As president-elect, Donald Trump seems determined to up-end this tradition. If not necessarily settling on irrevocable policies that will bind him in office, he is setting out a stall that could radically change US strategy.

It was the turn of Taiwan and its relationship to China on Friday. By taking a single phone call from Tsai Ing-wen, the Taiwanese president, and referring to her by that title, Mr Trump threw 40 years of established practice into question. In fairness, he is right — if indeed this is his aim — to point out America’s contradictory attitude to the self-governed and democratic island.