Of course, China's President Xi Jinping won't cancel his appearance at the East Asia Summit or the APEC leaders' meeting. He offers untold sums of money to countries of the region and a burgeoning navy as a premonition of power yet to come. By contrast, the US increasingly gives every impression it considers Asia to be an optional extra.

Even when American officials try to reassure their Asian allies that they are fully committed to the region, Trump's most serious cabinet officials like Defence Secretary Jim Mattis inadvertently send the signal that Asia is on the periphery of a shrinking American universe. Mattis said at the Shangri-La Dialogue in Singapore in June that "America is in the Indo-Pacific to stay" as it was the "primary theatre", yet he repeatedly referred to the region as "out here". Jim Mattis at the Shangri-La Dialogue. Credit:AP So Australia, among others, needs to make contingency plans for finding security in a region where the US is increasingly remote and China increasingly present.

Hugh White directs our attention to the invisible neighbour, the power next door, Indonesia. In a new essay, the ANU professor and former chief defence strategist for Australia points out that Indonesia "has the potential to be far more important to Australia than we have ever conceived". How so? In two ways. First is its gathering economic weight. "By 2030 - when Australia's new submarines may just be starting to enter service - its GDP will be three times Australia's, and almost as big as Japan's," he writes in the journal Australian Foreign Affairs. "Wealth is the ultimate foundation of national power, so that will make Indonesia, should make Indonesia, a very powerful country," according to White. Illustration: Dionne Gain Second is Indonesia's strategic potential. "Indonesia's growing power can be both good and bad news for Australia, making it both a more valuable potential ally and a more dangerous potential adversary."

White points out that while Indonesia is the only close neighbour strong enough to pose any serious threat to Australia, it's also the only one strong enough to help Australia "resist the intrusion of a potential adversary to within striking range of our shores". Whoever could he be speaking of? He's referring to China, of course. Indonesia has its own problems with China. Beijing and Jakarta both lay overlapping claim to part of the South China Sea, for instance, the source of some friction in the last couple of years. Indonesia could be "possibly the most important ally" Australia could have in holding China at bay. But if any such relationship is to evolve, it won't happen by itself. It has to be crafted by governments. And that means leaders. Illustration: Andrew Dyson Credit: So Scott Morrison did the right thing by keeping Malcolm Turnbull's appointment to travel to Jakarta on the weekend. The new Australian Prime Minister signed a trade and investment agreement with Indonesia's President Joko Widodo, know universally as Jokowi.

And also a "comprehensive strategic partnership". Despite its impressive title, this has nothing to do with strategic co-operation in the sense of a military alliance. It's more a friendship bracelet than a wedding ring. Former foreign affairs minister Julie Bishop. Credit:Alex Ellinghausen These are solid steps. But what's next in cementing a closer relationship? "It's got to be about intelligence and security," says Australia's former foreign affairs minister, Julie Bishop. "Australia and Indonesia can be part of a much tighter group with India and Japan," she suggests, putting four regional democracies together. Would the US have a place in such a group? "Maybe not just yet," she says, diplomatically, knowing that Indonesia, with its history as a leader of the non-aligned movement, couldn't accept such an association.

But, Bishop points out, "they are moving away from the non-aligned movement, and they're becoming much more wary of China. They're moving closer to India and Japan and with Australia it's a neat fit," she tells me. It certainly seems the right moment to strengthen the bonds of strategic trust. Not only are Australia and Indonesia both seeking security against the risk of a rising China, the two countries have no major disputes running and Jokowi is well disposed towards his big southern neighbour. Loading Replay Replay video Play video Play video Indeed, Jokowi has even left open the possibility of reviving the mutual security pact struck between Indonesia's president Suharto and Paul Keating in 1995. The treaty was torn up in anger in Jakarta's parliament in a display of nationalistic fervour during Australia's UN-sanctioned intervention into East Timor as it secured its independence from Indonesia.

Scott Morrison and Joko Widodo at the weekend. Credit:AAP But the treaty still stands in Australia and could be reinstated. Asked about the idea in a March interview with Fairfax Media, Jokowi was careful but not dismissive: "I think it depends on the government. If we want to make our relations stronger, it’s always from the government, always from the leaders. I’m sure if the communication is like now, we won’t have a problem in our relations." He faces re-election next year, as does Morrison. But this is an idea the two countries could return to. It would help defeat any potential turn to suspicion between the two neighbours. And even help create some stability in a region where that quality is fast shrinking. Peter Hartcher is international editor.