Indonesia’s strategic autonomy and the absence of Indo-Pacific trilateralism

15 May 2026

For more than eight decades, Indonesia, the US, and Australia have shared a maritime neighbourhood shaped by overlapping strategic interests. Although analysts have pointed to an Indonesia-US-Australia trilateral as a logical next step, no such framework has emerged. A trilateral alliance would entail mutual defence obligations, coordinated crisis-time planning, and a degree of strategic alignment that goes beyond ad hoc cooperation. Instead, the existing patterns of engagement — ranging from joint exercises and defence arrangements to maritime domain awareness programmes — remain limited to parallel bilateral frameworks rather than a unified strategic arrangement.

The absence of a trilateral partnership is a deliberate and enduring outcome of Jakarta’s foreign policy posture, reflecting its long-standing commitment to strategic autonomy under its bebas aktif (free and active) doctrine. Under this principle, Indonesia engages competing geopolitical powers without formal alignment to any. A trilateral framework with the US and Australia would risk signalling alignment in a great-power rivalry, particularly against China. As a result, while Jakarta has expanded defence cooperation with both Washington and Canberra, these relationships remain structurally bilateral. Indonesia has maintained this posture for over a decade, preserving its bargaining power and limiting the prospects for trilateral convergence or alliance formation.

If other middle powers in the Indo-Pacific follow Jakarta’s stance in resisting formal alignment, the region may become one where multilateral cooperation works in peacetime but falls short in crises, including grey zone escalation.

In August 2024, Australia and Indonesia signed a landmark defence agreement enabling more complex joint exercises and operational coordination. The US and Indonesia upgraded their relations to a Comprehensive Strategic Partnership in November 2023, expanding cooperation in training and maritime domain awareness. This was further reinforced by the US-Indonesia Major Defence Cooperation Partnership announced in April 2026, which deepens defence coordination and capacity-building while remaining firmly bilateral — without creating obligations that would anchor Indonesia within a trilateral structure. Together, these developments place Jakarta within two parallel, unintegrated bilateral frameworks. While Washington and Canberra seek interoperability and crisis-time coordination, such assurances from Jakarta remain absent. These arrangements deepen cooperation while preserving Indonesia’s strategic ambiguity, ultimately limiting reliable alignment in moments of crisis.

Indonesia’s deliberate ambiguity

Indonesia’s strategic posture is rooted in the bebas aktif doctrine, first articulated in 1948, which emphasises independence from formal alliances and flexibility in external relations. In practice, this doctrine is reflected in Jakarta’s reluctance to engage in bloc-based security arrangements: Indonesia has declined to join or endorse the Quad, viewing it as implicitly directed against China, and responded with similar caution to AUKUS, with then-Foreign Minister Retno Marsudi calling for transparency and reaffirming ASEAN centrality.

At the same time, Indonesia’s strategic ambiguity creates opportunities for external actors, with China actively engaging Jakarta within this space. During Prabowo’s November 2024 visit to Beijing, a joint statement on South China Sea development raised concerns in Washington over language that appeared to suggest Indonesia’s openness to joint resource exploration in disputed waters. US officials criticised the statement as undermining established positions on maritime claims, prompting Jakarta to clarify that it did not recognise China’s nine-dash line and that its broader position remained consistent with its non-aligned posture. This episode reflects Jakarta’s deliberate effort to avoid perceptions of strategic alignment with any great powers, even as the growing weight of Chinese investment in key sectors — particularly minerals, AI, and infrastructure development — raises the cost of neutrality and creates potential economic leverage that could constrain Indonesia’s decision-making in future crises.

A more recent illustration is Indonesia’s participation in Trump’s Board of Peace (BoP) initiative. Prabowo committed up to 8,000 troops for a Gaza stabilisation force, making Indonesia one of its most active contributors. Domestically, the move was framed less as alignment with Washington and more as an expression of solidarity with Palestinians. This engagement shifted after the US and Israel struck Iran in February 2026, prompting Indonesia to suspend its participation. Jakarta’s selective participation in the BoP reflects its pragmatic interpretation of bebas aktif: proximity to power without formal alignment, and active management of its strategic identity.

From its decision to stay out of the Quad and AUKUS to its calibrated engagement with the BoP, Indonesia’s commitment to non-alignment is not passive but a deliberate effort to preserve room to manoeuvre amid competing geopolitical pressures. The same logic underpins its caution towards trilateral convergence with the US and Australia.

What Washington and Canberra should not expect

Indonesia is a middle power of considerable geostrategic importance, making it an attractive partner in the region. Washington’s primary interests lie in access and contingency planning: the Lombok and Sunda Straits represent critical maritime chokepoints for US naval operations in the Western Pacific, and the Indo-Pacific Command has accordingly invested in Indonesia’s maritime domain awareness infrastructure and training facilities. US interests are thus less focused on securing alliance commitments than on ensuring that Indonesian maritime routes remain accessible.

For Australia, the strategic stakes are more immediate, as its northern approaches depend on the Indonesian archipelago. The 2026 Jakarta Treaty, committing both sides to consult during threats, reflects Indonesia’s central role in Australia’s strategy. Yet consultation alone does not ensure cooperation. Its effectiveness hinges on whether Jakarta moves beyond dialogue to operational protocols, crisis coordination, and some commitment of forces — steps constrained by its preference for strategic autonomy. With Australian power projection relying on Indonesian waters, Jakarta’s posture is a decisive variable in Canberra’s contingency planning.

Trilateral integration thus remains unlikely. Washington and Canberra cannot read Indonesia’s bilateral warmth as a proxy for crisis-time reliability: a cohesive trilateral framework would require predictable alignment in crisis scenarios, a commitment Indonesia has consistently avoided. On the South China Sea, the most likely flashpoint for regional conflict, Indonesia has repeatedly refused to signal which side it would take. Jakarta would likely invoke bebas aktif, prioritise de-escalation through diplomatic channels, and refrain from explicit alignment.

The case for half a partnership

The three countries find common ground most easily in functional cooperation — practical coordination that avoids formal defence commitments, integrated command structures, and binding obligations. This arrangement suits Indonesia’s preference for strategic flexibility, allowing Jakarta to maintain its non-aligned posture. But such cooperation may prove fragile in times of crisis.

The risk is tangible. If China intensifies pressure in the Natuna Sea — through coast guard activity, fishing incursions, or direct confrontation with Indonesian vessels — Jakarta would be forced into a difficult position. Accepting implicit support from the US or Australia, as a formal trilateral structure would demand, could come at the cost of provoking diplomatic fallout with Beijing and undermining the very hedging strategy Indonesia seeks to preserve.

Indonesia and Australia’s expansion of their security cooperation to include Japan and Papua New Guinea in March 2026 likewise reflects a non-aligned approach, framed by Indonesian Defence Minister Sjafrie Sjamsoeddin as professional rather than political. The result is a networked architecture of practical cooperation — density without commitment — addressing shared maritime concerns such as illegal fishing and sovereignty while preserving Indonesia’s strategic flexibility and avoiding explicit alignment against China.

If other middle powers in the Indo-Pacific follow Jakarta’s stance in resisting formal alignment, the region may become one where multilateral cooperation works in peacetime but falls short in crises, including grey zone escalation. This may not match Washington’s vision of the Indo-Pacific, but it is likely closer to what Southeast Asia is willing to sustain. Washington and Canberra would be better served by planning for that reality than by treating Indonesia’s limited cooperation as a problem to be solved through more exercises, more investment, and more diplomatic reassurance.

The absence of a trilateral partnership between Indonesia, the US, and Australia is likely to persist. Jakarta’s adherence to bebas aktif ensures that cooperation will continue to expand through bilateral and functional channels while stopping short of the formal alignment a trilateral framework would require. For Washington and Canberra, this necessitates a recalibration of expectations. Indonesia is not an incomplete ally in the making, but a partner that deliberately limits the depth of its strategic commitments. Recognising what Indonesia genuinely offers — functional cooperation, geographic access, and peacetime partnership — means abandoning expectations of eventual trilateral convergence. Indonesia is not a partner that has failed to become an ally; it is one that has consistently chosen not to be.

DISCLAIMER: All views expressed are those of the writers and do not necessarily represent those of the 9DASHLINE.com platform.

Author Biography

Muhammad Izzuddin Al Haq is a graduate of International Affairs Management at the School of International Studies, Universiti Utara Malaysia, and was a Cadet Researcher at AIIAD and Director-General of World Order Lab. His analysis focuses on international security and global governance, and has appeared in East Asia Forum, Australian Outlook, Stratsea, Pacific Forum, and others.

Image Source: DVIDS