Agency preservation drives the Indonesia–Australia security treaty

The echoes of history are evident – only this time, trust may not be as important as the context.

Emirza Adi Syailendra

17 November 20255 min read

The last time Australia and Indonesia celebrated a security pact – the 1995 Agreement on Maintaining Security (AMS) – it ended poorly. The new Treaty of Common Security echoes that moment, but history reminds us: shared optimism can mask diverging interests.

The AMS wasn’t born of strategic necessity; it was designed for optics. For Australia, then prime minister Paul Keating pushed it as an election-year gambit, a bid to look statesmanlike and cement his legacy. It failed. Indonesia’s president Suharto framed his approval as helping a friend, but it sidelined the Foreign Ministry. Implementation lagged, trust never solidified, and by the late 1990s, it was effectively dead.

The final blow came in 1999, when Australia led INTERFET – the UN-backed mission to East Timor after post-referendum violence. The AMS collapsed over Australia’s choice to preserve its agency, despite Jakarta’s expectations for support.

Fast-forward to today, the resonances of the AMS are unmistakable, but the new deal is a different creature altogether. A treaty signals a stronger commitment than an agreement, and while the 2025 version borrows from the AMS template, its ambitions are larger – elevating consultation to the leaders’ level, not just ministers. And unlike the AMS, where then foreign minister Ali Alatas was sidelined, the new treaty was shaped directly by both leaders and their foreign ministers.

This is still a story of two countries choosing their own interests.

Most importantly, while the AMS was driven by politics, the latest treaty is driven by strategic necessity. The idea of “Common Security” signals that Australia and Indonesia share fundamental concerns about the regional environment, even if they do not recognise a common threat. It conveys a shared anxiety: as US policy leans on allies and partners to curb Beijing’s rise, both countries struggle to navigate their deep economic ties with China while trying to limit its coercive influence.

As US–China competition becomes zero-sum, East Asian states are increasingly looking sideways, talking about autonomy and agency.

In Australia, the lexicon of strategic autonomy has surged in recent years. “Agency” now represents a growing desire in Canberra for a more independent foreign policy – still allied to Washington, but less dependent. Australia has been stitching together a web of relationships – from Tuvalu to PNG – to secure greater agency in a volatile region. But Jakarta is different. Indonesia is one of the few countries in Asia with real historical weight in shaping regional order.

For Indonesia, preserving agency is no longer a slogan; it has become a matter of strategic survival. Jakarta has been repeatedly hit by erratic great-power behaviour: US tariffs, “America First,” and the CHIPS Act have undercut Indonesia’s industrial ambitions and pushed firms such as LG Energy Solution to withdraw, narrowing Jakarta’s room for manoeuvre. Even as Indonesia deepens its ties with China, Beijing’s growing leverage – seen most clearly in its push for lithium iron phosphate battery production that sidelines Indonesia’s nickel advantage – has raised fears of entrapment.

Still, a treaty with a staunchly non-aligned state is not routine diplomacy. It is as close as Indonesia has ever come to an alliance. Unlike Singapore, whose Defence Cooperation Agreement with Indonesia relies on Association of Southeast Asian Nations (ASEAN) membership and close economic ties, Australia’s treaty with non-aligned Indonesia was enabled by a uniquely ripe moment. Great power coercion and President Prabowo Subianto’s centralised authority opened a window unlikely to recur in peacetime. While Prabowo seeks alignments with multiple partners, the shared history of regional order-building through ASEAN mechanisms and official ties at all levels remains a distinctive feature of the Indonesia–Australia relationship.

Prabowo Subianto at the Heroes' Cemetery at Kalibata, South Jakarta, Indonesia, 10 November 2025 (@prabowo/X)

The devil is in the details. The new treaty is relationship dependent: its strength lies not in law, but in the evolving relationship and the fulfilment of tacit expectations. The closest model is the US–Australia alliance; the Five Power Defence Arrangements is too multilateral and institutionalised to compare.

The Australia, New Zealand, United States Security Treaty (ANZUS), on which the 1995 AMS was modelled, began as a commitment to consultation. Its strength has always derived from lived expectations: that the United States would neither abandon nor entrap Australia, and that Australia would reinforce US leadership. In practice, consultation and concerted action could be achieved without a formal alliance – but the treaty provides a moral and institutional framework. The treaty between Indonesia and Australia works the same way: a slim document that expands or contracts depending on how both sides meet tacit expectations.

Therein lies the difference between ANZUS and the Treaty of Common Security. Even without explicit guarantees, both ANZUS parties are strongly assumed to act against common threats, guided by the logic of extended deterrence. By contrast, the new treaty is grounded in an assumption of an interdependent security ecosystem: each side links its security to the other’s and avoids actions that might make its partner feel insecure.

In uncertain times, when the order itself is unstable, interests take priority and countries look past differences.

For Australia, the expectation is that Indonesia will prioritise the security partnership, reinforce shared interests, and at minimum, abstain from undermining Australia’s efforts – whether in policy or through practical measures such as naval deployments – to preserve regional order. In return, Canberra must consult, uphold defence commitments, and respect Indonesia’s sovereignty. The challenge: would closer defence ties require deeper trade and investment with a country perceived as too close to Beijing?

For Indonesia, the expectation is that Australia will act as a dependable security partner, even under Washington’s pressure, and that engagement will support Jakarta’s strategic autonomy beyond defence. Jakarta also expects respect for non-alignment, including keeping its waters out of potential war theatres. The challenge: will this warmth deliver tangible gains – in cattle trade, lithium processing, or other economic areas? If not, disappointment is inevitable.

Then there’s the shadow of East Timor. For Indonesia, it carries the image of Australia’s unreliability. Even in 2024, the mere suggestion of a Status of Forces Agreement met strong resistance from Jakarta.

Indeed, stakes – and suspicions – are high. Can Indonesia trust Australia to prioritise their partnership over Washington? Can Australia trust a partner that refuses to treat China as a strategic threat or pursue balancing measures?

Yet the importance of trust may be overstated. It matters in stable times – the AMS collapsed during a unipolar era. In uncertain times, when the order itself is unstable, interests take priority and countries look past differences.

As before, this is still a story of two countries choosing their own interests. It just so happens that, this time, agency preservation brings them together. The real test lies ahead: will both sides meet their tacit expectations—and bear the political costs that come with doing so?

About the author

Emirza Adi Syailendra

Emirza Syailendra is a Postdoctoral Research Fellow at the Maritime Security Programme, S.

Topics

Indonesia Australia Defence & security