Australia's strategic posture in the Indo-Pacific is being reshaped through deliberate engagement with regional powers, moving beyond Washington-centric alliances to build broader partnership networks. The most significant signal of this shift came in February when Prime Minister Anthony Albanese signed the Australia-Indonesia Treaty on Common Security at Merdeka Palace in Jakarta, formalising a commitment to regular leadership and ministerial consultations on shared security challenges.
The treaty commits Australia and Indonesia to consider "measures which might be taken either individually or jointly" if either nation faces adverse security developments. More tangibly, it authorises the development of joint defence training facilities in Indonesia and provides for enhanced intelligence sharing between the two countries. This represents the most significant deepening of the bilateral partnership in 30 years, according to Foreign Minister Penny Wong.
Within weeks, the architecture expanded. In early March, Australian Defence Minister Richard Marles met Indonesian Defence Minister Sjafrie Sjamsoeddin in Jakarta to announce two trilateral security arrangements: one bringing together Australia, Indonesia and Japan, and another linking Australia, Indonesia and Papua New Guinea. Both will focus on "defence professionalism", a euphemism that signals cooperation on training, doctrine, interoperability and intelligence standards.
The strategic implications are significant. Indonesia is the region's largest economy and most populous nation, with substantial armed forces and geographic proximity to critical sea lanes. Getting Indonesia to anchor itself within multiple Western-aligned security frameworks represents a genuine achievement in Indo-Pacific statecraft. The inclusion of Japan and PNG extends the network further, creating nodes of interoperability that link maritime security across Southeast Asia and the South Pacific.
A practical embodiment of this is the proposed joint defence training facility on Indonesia's Morotai Island in North Maluku Province. The facility, which will remain under Indonesian sovereignty, will allow Australian military personnel to train alongside Indonesian and other partner forces. Australian Defence Minister Marles confirmed that an Army survey team will visit the island by the end of 2026 to map infrastructure expansion plans, with construction likely commencing in 2027.
The timing matters. These announcements come as Australia navigates a complex strategic environment where the United States remains the principal alliance partner through AUKUS, yet regional middle powers increasingly expect Australia to embed itself within localised security architectures rather than importing solutions. Japan's inclusion in a trilateral with Australia and Indonesia, for instance, reflects Tokyo's own concerns about managing Chinese pressure and maintaining stability across multiple theatres simultaneously.
Australia's approach differs subtly from Washington's traditional hub-and-spoke model. Rather than Indonesia being a spoke to Australia's hub, these trilateral arrangements position Indonesia as a connector linking Australia to Japan and PNG. This topology distributes influence more evenly and gives Indonesia greater agency in shaping regional outcomes. That is why Indonesian Defence Minister Sjamsoeddin has publicly embraced the arrangements while emphasising that they operate on the basis of "consultation over blocs" rather than formal alliances that would alienate China.
From a national security perspective, Australia's calculation appears to be that deepening relationships with regional powers creates more resilient deterrence than relying on distant allies alone. The Morotai facility particularly signals confidence in Indonesia as a long-term partner, since Defence Minister Marles explicitly acknowledged that upgrading Indonesian military infrastructure serves Indonesia's interests first. This approach trades some autonomy for regional acceptance, which may prove durable in ways that more transactional partnerships do not.
The counterargument is whether Indonesia's commitment to the arrangement remains solid as its own strategic environment shifts. Indonesia's recent election saw the return of retired general Prabowo Subianto as president, a figure with longstanding ties to defence establishments across the region. His support for these arrangements appears genuine, yet they represent a significant tilt toward Western-aligned security cooperation that Indonesia's previous governments might have resisted. The durability of these partnerships will depend on whether Australia remains seen as a beneficial presence rather than an extension of strategic competition between great powers.
Australia's defence spending is projected to grow 5.9 per cent annually through 2030, with much of that investment supporting AUKUS commitments. The expansion of regional partnerships through Indonesia and Japan suggests that Australia is simultaneously investing in both the alliance with the US and relationships with regional powers. This dual approach carries real resource implications but appears to reflect a judgment that neither layer alone provides sufficient deterrence against the range of challenges Australia faces in the Indo-Pacific.