With Donald Trump’s inauguration as president of the United States fast approaching, the strangest — even craziest — post-election transition in US history is about to come to an end.

This period has provided a clear demonstration of how unpredictable life with President Trump will be.

A president-elect typically uses the transition time to make Cabinet choices and to study the issues he will soon confront, but keeps quiet on policy until he has been sworn into office.

But Trump has only paid lip service to the hallowed principle that the US has just one president at a time. Shortly after the election, he began to conduct his own foreign policy.

Just a couple of weeks after becoming president-elect, Trump took to Twitter to suggest that the British government name Nigel Farage, who had led the successful Brexit campaign, as the United Kingdom’s ambassador to the US.

Trump may have been unaware that governments choose their own ambassadors, and that the esteemed Sir Kim Darroch was already ensconced in the British embassy in Washington, DC. (The UK government quickly announced that Darroch would stay on.)

Soon thereafter, Trump took a congratulatory call from Taiwanese President Tsai Ing-wen — a sharp departure from the “one China” policy that presidents, Democratic and Republican alike, have upheld for more than 40 years.

China strongly condemned the move — and Trump’s subsequent tweets questioning America’s commitment to the one China policy.

Trump’s foreign-policy meddling reached its apex — at least so far — in late December, when he tried to interfere with President Barack Obama’s administration’s decision to abstain from voting on a United Nations Security Council resolution condemning Israel for continuing to build settlements in occupied Palestinian territories.