To make it as humiliating as possible for his ally, he did it on the weekend in public, with the media, while standing on Japanese soil, a special Trumpian touch of contemptuousness. After saying all the right things to Japan's Prime Minister, Shinzo Abe, on Friday, on Saturday Trump left his host a "stink bomb", in the words of The New York Times. Trump said of the US-Japan security treaty: “I told him, I said, ‘We’re going to have to change it'.” He revealed this to reporters and promptly flew out to ingratiate himself with Kim. Who wins from this? The only winners are Japan's enemies, North Korea and China, the countries that also happen to be America's rivals. Illustration: Andrew Dyson Credit: Why should Australia care? Because "Japan faces exactly the same dilemma as Australia", says Australia's former chief military strategist, Hugh White. But Japan faces it "only more acutely" because of the continuous and intensifying Chinese air force sorties that challenge Japan's sovereignty. By destabilising Japan's security treaty, Trump only encourages China to go harder.

And what is that dilemma? "Whether the dependence on the US that has worked since 1945 can continue," says White. And, to be clear, he thinks that Australia is kidding itself. Australia is foolish to rely on America and needs urgently to arm itself, he argues. Because White, professor emeritus of strategic studies at ANU, says that Australia today can not defend itself against a major adversary, and cannot expect the US to ride to its rescue. In fact, he's written a whole book on the topic, titled: How to Defend Australia. He argues that Australia needs a major military rearmament. He estimates that, to provide a credible independent defence of itself, Australia needs to increase its annual defence outlay from 2 per cent of GDP to around 3.5. That implies an extra $23 billion a year in the defence budget, using current dollar values. It's a level Australia needs to reach in the next five years or so, 10 at most: "Time is not on our side." To avoid this reality is a shocking abrogation of responsibility. Future historians will "wonder why we have done so little for so long to respond trends that have been so clear". Loading What trends? As the US loses power relative to China, and as America's will to dominate Asia fades, Australia's US alliance will "weaken, and quite possibly disappear, as our alliance with Britain weakened and disappeared", he writes. "But this time, if that happens, there will be no new 'great and powerful friend' to take its place. We will really be on our own." White simplifies the Australian decision into "essentially a choice between being a middle power or a small power". How so? "Middle powers can stand up to a great power without the backing of another great power, while small powers cannot." White doesn't blame Trump entirely: "Trump is not the driver" of America's retreat, he tells me, "but it's been very sharply accelerated by Trump's behaviour." The underlying historical driver "is the direct result of the biggest change in the global distribution of wealth and power in 200 years, which has brought to a close the era of Western domination of East Asia that began with Britain's Industrial Revolution - and will end with China's".

If anything, Trump might even have done us a bit of a favour by exposing the underlying reality of American will: "Donald Trump did what we all thought was impossible - he got elected president without a commitment to retaining US global leadership," White says. "It turns out that, once you get outside the Beltway [of Washington's inner workings], no one much cares about it." He puts the US Democrats into the same category. White was long a part of the Canberra establishment, Australia's own "inside the Beltway", or what Scott Morrison likes to call the "Canberra bubble". He was deputy secretary for strategy of the Defence Department and an adviser to Bob Hawke and Kim Beazley. Yet he now says that the Canberra establishment is deluded: "Our foreign policy and defence establishment continues to cling to the vision of US global leadership, and they reinforce that by talking to everybody inside the Beltway. So they miss the broader point - the meaning of Trump. It's not just a problem this year or next year. It's a 20 or 30 year problem," he says. Loading White goes so far as to say that Australia needs to debate the option of arming itself with nuclear weapons. His book devotes a chapter to the topic. If Australia can't rely on America to defend it in a conventional war, "then we certainly can't depend on it to accept the far greater burden of defending us from nuclear attack either", he writes. He doesn't endorse the nuclear option for Australia - he says it's a "debate we have to have", but argues that we have some years before we need to resolve it. "I do back off from that one," he tells me, "because it scares me". The entire subject of Australia's military vulnerability is a scary one, one Australia has been avoiding. White does us a favour by making Australia look beyond Trump and confront it.