This week at California’s Stanford University – about as far from the White House as possible – Australia’s foreign affairs and defence ministers held two days of talks with their US counterparts.

Typically, this annual meeting receives little public attention. It is, like the Australia–United States alliance itself, an unremarkable and uncontentious fixture of the nation’s conduct of foreign affairs. Such lack of interest has long been a measure of the alliance’s apparent stability and immutability.

But this has changed since the election of Donald Trump, who has introduced an element of contingency into Australia’s relationship with its closest ally. This erratic president delights in pandering to enemies and attacking friends, and he makes it harder for Canberra and Washington to follow the same script.

Trump is not the only source of pressure on the alliance. The greater challenge – which will continue long after the forty-fifth president moves back to his tower – is the rise of China, which threatens the grand prize that Australia has long received from its close US ties: security in Asia.

These two challenges – Trump and China – hovered over this week’s talks and the future of the seventy-year-old alliance.

Defense Secretary James Mattis, assuring Australia that the United States remains committed to the region, said at a press conference after the talks: “The US and Australia will walk the walk in the Indo-Pacific.”

Australia’s foreign minister, Julie Bishop, responded in kind: “We don’t always agree with the US and the US doesn’t always agree with us, but we are able to work through any differences.”

But Australian leaders have struggled to work out how to handle Trump. Since the leaked phone conversation last year in which Trump berated Malcolm Turnbull for a refugee deal between the two countries, the Australian prime minister has been at pains to avoid confrontation with the US president. This has led to some strange contortions, such as Turnbull’s description last week of Trump as a “patriot” – after the US president chose to trust Vladimir Putin over the assessments of his own national intelligence agencies.

Bishop has been more forthright, particularly about the need to take action against Putin over the Russian-backed missile attack on the Malaysia Airlines MH17 flight above Ukraine in 2014. The attack killed 298 people, including thirty-eight Australians. Before the talks in Stanford, Bishop noted Trump’s “unorthodox approach to foreign policy” and said she wanted to hear from her US counterparts “directly about the president’s approach and what he has achieved by it”.

Trump’s approach is unpredictable and risky, and his willingness to undermine relations with countries such as South Korea and Japan – as well as his support for authoritarians and autocrats, and his resistance to international treaties and cooperation – are not in Australia’s interests. Australian leaders should say so, without contortion.

Canberra has long been reluctant to openly challenge Washington. This approach – though it sometimes lapses into slavishness – has a recognisable purpose: it is designed to strengthen the alliance and ensure the continued support and commitment of the world’s most powerful nation. The trade-off led Australia to follow the United States into wayward missions in Iraq and Afghanistan, even if these distant conflicts had only indirect links to Australia’s self-defence.

But if, or as, the value of being a US ally declines, Australia’s willingness to pay a high price, including deaths of its soldiers, for the broader benefits of the alliance may become difficult to justify. 

As China’s wealth and power increases and it challenges the status of the United States in the Asia-Pacific region, there are questions about the extent of Washington’s commitment to remaining a dominant force in Asia.

China’s rise does not mean the Australia–United States alliance will necessarily end. There are many foundations that have helped to sustain it, such as Australia’s affinity with US culture and respect for its role as a liberal democracy and a guarantor of a stable, lawful international order in Asia since World War II. If Australia deems China a threat, it may try to cling more closely to the United States, as long as it knows it can rely on Washington’s support.

Trump is undermining each of these foundations, and his style of leadership only adds to the uncertainty. His oldest allies should do all they can to resist his worst impulses. For Australia, this may sometimes involve speaking openly and directly to Washington – even if it risks the ire of Trump or threatens to disrupt the traditional displays of easy accord.