The government’s decision to significantly expand the Royal Australian Air Force’s key northern base near Katherine, around 300 kilometres southeast of Darwin, is a giant strategic step forward and will deliver a firmer deterrent posture and a closer alliance with the US.

A stronger defence posture in our north could also be the basis for a greater Australian leadership role in the region, where we can work with our key Southeast Asian partners—Indonesia, Singapore, Malaysia, and hopefully Vietnam—in a shared strengthening of the region.

Especially valuable is that the enhancements at RAAF Base Tindal are planned to be finished by 2027. In contrast, on current plans, the first of our Attack-class submarines will still be nine years from entering service by then.

The importance of the new submarines should not be underestimated, but the security situation in the region is changing so fast that Australia needs to urgently boost its military strike power and strengthen its deterrence capability. There is no better or quicker way to do this than through air power and the US alliance.

I’m very positive about this military strengthening, not least because a decade ago I led the Defence Department effort to expand cooperation with the US in northern Australia.

There were three reasons for establishing a US Marine Corps presence in the north and planning for increased cooperation between our air forces and navies.

First, it added a new dimension of closer cooperation with the US, deepening American engagement in, and commitment to, Australian security. This is a hugely valuable deterrent asset for Australia, one that complicates the planning of any potential adversary.

Second, this cooperation will modernise the alliance and make it better suited to handle emerging threats. The northern focus will be on having the ability to rapidly disperse and deploy forces over large distances, extend the range of combat hitting power and bring our military forces into more effective high-technology cooperation.

Third, enhanced northern cooperation is a strong signal of American and Australian interest in the security of Southeast Asia.

Geography doesn’t change. Southeast Asia was the strategic fulcrum around which the Pacific War was fought, and it is the region most sharply in Beijing’s sights as the Chinese Communist Party seeks to weaken America’s security leadership in the Asia–Pacific.

A much sharper strategic competition for influence is building in Asia between the US and China. Australia can’t opt out of this reality. Washington and its key allies in the Indo-Pacific—Japan and Australia—need to give the wider region some confidence that collectively we can push back against Beijing’s bullying.

The bones of the enhanced northern defence cooperation plan were shaped in early 2011 and announced in November of that year in Darwin by US President Barack Obama and Prime Minister Julia Gillard. We should have done a better job of bringing Indonesia into the discussion, and Indonesia’s president at the time, Susilo Bambang Yudhoyono, did Canberra and Washington an enormous favour by graciously accepting what he knew to be a positive strategic development for the region, notwithstanding the lack of consultation.

Learning from that mistake, Prime Minister Scott Morrison should brief President Joko Widodo quickly. He must surely have been given a heads-up about the Tindal development on his recent Canberra visit.

Jokowi’s speech to the Australian parliament, in which he said ‘Australia adalah sahabat paling dekat Indonesia’, meaning ‘Australia is Indonesia’s closest friend’, is not an expression of friendship so much as a statement of shared strategic risk.

In contrast to the strategic outlook of two decades ago—when East Timor’s independence loomed large and trust between Canberra and Jakarta was abysmally low—this new stage of defence interest in Australia’s north can involve Indonesia as a vital partner.

Of course, the most dramatic difference between the strategic situation at the time of the Obama–Gillard announcement and today is China.

In 2011, Xi Jinping had yet to become president, and was yet to assume permanent personal control of the CCP and purge its and the military of his rivals. China had not yet annexed the vast bulk of the South China Sea, where it built three substantial military bases that have brought Chinese air and maritime power into the heart of Southeast Asia.

In 2011, China was well down the track of modernising its military forces but few Western analysts at that time would have imagined how far and how quickly the People’s Liberation Army would develop in less than a decade.

China’s reaction to the expansion of Australian and American air power out of RAAF Base Tindal and Darwin will take two forms—one public and one private.

Publicly, Beijing’s diplomats, PLA senior colonels and editorial writers will berate Australia for ‘Cold War thinking’, for failing to appreciate the benign intent of the Belt and Road Initiative and for misrepresenting China’s honourable and defensive cyber espionage operations.

In Australia, a variegated collection of China boosters, US alliance haters and people determined to see in our modest defence companies a ‘mini-me’ military–industrial complex, will complain about the government’s initiative and, indeed, about ASPI’s gall in talking frankly about the strategic risks posed by an assertive, authoritarian China.

Can Beijing’s response and its domestic echoes be completely unconnected? China’s palpable decision to turn the diplomatic dial to ‘loud and angry’ has been noted around the world.

It seems that any national expression of independence not completely aligned with ‘Xi Jinping thought’ will be aggressively refuted. Any attempt to enhance Australian and American military cooperation—which has been at the core of our defence policy since before the communist take-over in China—will be treated as an affront by Beijing.

None of that should matter to Scott Morrison. A more private Chinese leadership reaction will be to regard the Tindal announcement as a logical strategic response to China’s influence-building in Southeast Asia.

Beijing’s strategic planners are opportunistic realists. They understand how to make tough judgements based on national interest and they will see the Tindal announcement in that light.

China views Australia’s defence alliance with the United States with a mix of envy and puzzlement. Beijing is envious because the alliance gives Australia access to a trove of technology and information that China could never source through willing partnerships. Its puzzlement is about how countries can cooperate so effectively based on trust, strategic interest and shared values. China does not have these types of relationships.

What should happen next in Australia–US defence cooperation in northern Australia? There’s certainly scope to expand the Marine Corps’ footprint from its current level of around 2,500 personnel annually.

Australia is also well placed to offer sophisticated air-training ranges in the north to countries that, like us, are buying the F-35—Japan, South Korea and Singapore.

At the heart of all these trends is the increasing need for weapons with extensive range. Finding a weapon that can push the Australian Defence Force’s strike power and deterrent effect well north of the Indonesian archipelago is the next essential task for defence planners.

Finally, there’s the Port of Darwin, which is now in year five of its 99-year lease to a Chinese company. How long will that odd deal last in an emerging regional order which makes northern Australia more strategically significant to us, our allies and our neighbours?