On Friday this week Kevin Rudd wrote an analysis of China's potential response to the incoming Trump administration, noting that what Beijing feared most was uncertainty.

The following day the president-elect's transition team issued a jaunty statement confirming that Donald Trump had arbitrarily upended 35 years of careful American diplomacy by speaking on the phone with the President of Taiwan, Tsai Ing-wen, conceivably putting the United States on a path that ends in direct confrontation with China over one of the most explosive geopolitical flashpoints on earth.

It is difficult to exaggerate how significant - and how provocative - this action was. China considers Taiwan to be a rogue province and has declared that it would go as far as using military force to prevent Taiwanese independence. The US has for a generation danced a careful dance in support of Taiwan. It is the de facto guarantor of Taiwanese defence, but it does not recognise Taiwan as an independent state. No US leader has officially spoken with a Taiwanese president in decades.

Into this fraught diplomatic charade, Trump bounded this week. After the Financial Times newspaper discovered that Trump had made the call, the President-elect's transition team confirmed that he had spoken with Tsai and "noted the close economic, political, and security ties" between Taiwan and the US.