President-elect Donald Trump’s decision to take a phone call from Taiwanese President Tsai Ing-wen has reinforced existing concerns about his ability to handle the complex intricacies of international diplomacy. While one phone call will not undermine America’s formal One China policy, it is a sign of the unpredictability likely to be inherent in the Trump administration’s conduct of foreign policy.

At one level, Trump’s decision to engage directly with Taiwan’s president can be seen as a positive development. Taiwan is, after all, a successful democratic state in Northeast Asia that has withstood many pressures from the communist mainland, which has at times attempted to bully Taipei into submission. Influential members of the US Congress have argued that administrations in Washington should be less deferential to authoritarian elites in Beijing and more willing to support Taiwanese democracy in public.

Yet, since the 1970s, the US has remained a major supplier of high-tech weaponry to Taiwan. The most recent arms package – approved by President Obama in December 2015 – totalled nearly $2.5 billion of sophisticated kit. This arms supply is aimed at promoting a defensive order of battle equilibrium. This is designed to persuade Beijing that its capacity to coerce Taipei is limited and that any military action against Taiwan would yield unacceptable costs for China, even in the event US intervention was not forthcoming.

It is also designed to reassure Taipei that it doesn’t need to take unilateral steps such as developing an independent nuclear weapon, which Taipei began to explore under its Hsin Chu program launched in 1964.

Read the full “Trump’s Taiwan chat a wake-up call for Australia’s national security establishment” article in the Financial Review by Andrew O’Neil, professor and dean in the Griffith University Business School.