Originally published in ANZSIL Perspective on 27 April 2026, co-authored with Associate Professor Danielle Ireland-Piper.
What is the Jakarta Treaty?
The Australia–Indonesia Treaty on Common Security (the Jakarta Treaty), which contains a duty to consult, was signed by Australian Prime Minister Anthony Albanese and Indonesian President Prabowo Subianto in Jakarta on 6 February 2026. The Jakarta Treaty was preceded by an upgrading of the existing Defence Cooperation Agreement in 2024 and moved to signature only months after it was announced in November 2025. This move sits alongside a range of other bilateral agreements that Australia has established or upgraded throughout the Indo-Pacific since 2022, including the Joint Declaration on Security Cooperation with Japan, the Papua New Guinea–Australia Mutual Defence Treaty (the Pukpuk Treaty), the Falepili Union with Tuvalu, the Nakamal Agreement with Vanuatu, a Status of Forces Agreement with Fiji, and a Defence Cooperation Agreement with Timor-Leste. An earlier Bilateral Security Treaty with Solomon Islands was also established in 2017.
The body of the treaty itself has only four articles, one of which is merely procedural. In Article 1, the parties undertake to engage in high-level consultation on matters of “common security” and to the development of cooperation that benefits regional security, but also the individual security of each of Australia and Indonesia. Article 2 similarly commits to “undertake to” consult on “adverse challenges to common security” interests. In Article 3, the parties agree to promote (“in accordance with the policies and priorities of each”) “mutually beneficial cooperative activities in the security field” in areas identified by Australia and Indonesia. Article 4 simply provides for entry into force.
Common Security
The term “common security”, occurring both in the title and the substantive articles of the Jakarta Treaty, is generally accepted to derive from the 1982 report of the Independent Commission on Disarmament and Security Issues, also known as the Palme Commission. That report posited “common security” as the antidote to “the false premise that security can somehow be gained unilaterally”, and instead reflective of the “selfish recognition that security can be attained only by common action”. In turn, common security requires the “renunciation of unilateral advantage” and the (presumed) reality that “we face common dangers and thus must also promote our security in common”.
A 2022 publication on ‘Common Security in the Indo-Pacific region’ reaffirmed six principles to preventing war and to building a more just and secure Indo-Pacific order: 1) All people have the right to human security: freedom from fear and freedom from want; 2) Building trust between nations and peoples is fundamental to peaceful and sustainable human existence; 3) There can be no common security without nuclear disarmament, strong limitations on conventional weapons, and reduced military expenditure; 4) Global and regional cooperation, multilateralism and the rule of law are crucial to tackling many of the world’s challenges; 5) Dialogue, conflict prevention, and confidence-building measures must replace aggression and military force as a means of resolving disputes; and 6) Better regulation, international law, and responsible governance also need to be extended to cover new military technologies, such as in realms of cyberspace, outer space, and “artificial intelligence.” These notions are not necessarily reflected in the Jakarta Treaty, but the need to build trust between nations, as articulated in principle two, is nonetheless advanced because of the specific framing around common security.
Arguably, this use of the term “common security” in the Jakarta Treaty points to an acceptance (or “selfish recognition”) by both Australia and Indonesia that security cannot be achieved alone. Even “national” (as opposed to international) security requires cooperation (in any event, there is no common and consistently accepted definition of “national security” at international law, though many treaties contain national security exceptions). In the context of challenges to the international rules-based order, this language points to a pragmatic preservation not only of independence, but the need to cooperate for the betterment of each nation and of the region.
Duty to Consult?
The primary legal obligations in the Jakarta Treaty relate to commitments to consult. The word used in the English version is “undertake” to consult. In theory, there could be a legal argument about the nature and extent of the duty, and if and when a breach were established, what remedial action would be required to remedy that breach (for example, cessation or assurance of non-repetition under the laws of state responsibility). In Pulp Mills on the River Uruguay (Argentina v. Uruguay) (Judgement), the ICJ was prepared to accept that commitments to consult and notify between countries can give rise to certain procedural obligations, in addition to substantive legal obligations. Article 31 of the Vienna Convention of the Law of Treaties also sets out the interpretative context of treaties.
For example, to what extent would Indonesia be obliged to consult with Australia on actual or perceived security threats from within West Papua, and how would Australia respond, given its own human rights obligations? Or conversely, would Australia be expected to consult with Indonesia on its relationships with the US and China? The terms of the treaty would suggest not, particularly the words “adverse challenges to common security”, which would presumably carve out individual challenges from the purview of undertakings to consult. Climate change, however, is widely recognised as a national security threat and a disruptor for armed forces and society as a whole. It is inherently a common threat, so what obligations arise in relation to emissions? If cooperation under the treaty gave rise to conduct that involved an internationally wrongful act, that may raise issues of joint responsibility for the purposes of the law on state responsibility. However, this is unlikely because of the framing in the preamble.
The Preamble
While preamble material is not binding at international law, it plays an important interpretive role, including in determining the intent of the parties, as well as signalling the relevance of other treaties. As Article 31(2) of the Vienna Convention on the Law of Treaties notes, “The context for the purpose of the interpretation of a treaty shall comprise, in addition to the text, including its preamble and annexes” (see also, the Beagle Channel Arbitration).
The preamble of the Jakarta Treaty recognises a common commitment to regional peace and stability, and asserts this can only achieved through “collective responsibility”. It also includes commitment to “ASEAN centrality” and the “rules-based regional architecture that upholds international law.” The preamble also includes a pragmatic call to be “mindful” that cooperation between Australia and Indonesia in the development of effective national capabilities in the defence field can contribute to “their own security”, that of the region, and in turn, therefore, to “national resilience and self-reliance.” Sovereignty, unity, independence and territorial integrity, and principles of good neighbourliness and non-interference all get a mention, as does the Charter of the United Nations; the Treaty of Amity and Cooperation in Southeast Asia; and the 1982 United Nations Convention on the Law of the Sea. Given that preambles are also used to explicitly signal the relevance of other treaties, it is significant that the Jakarta Treaty expressly references three other instruments. In short, any undertakings to consult will be constrained by references to, for example, sovereignty and non-interference, “national resilience and self-reliance”, as well as obligations contained in the UN Charter.
Historical and political context
A unique aspect of the Jakarta Treaty, which, unlike the Pukpuk Treaty, is not a formal alliance, is that it explicitly hearkens back to an earlier attempt to embed formal bilateral ties. In this case, the 1995 Agreement on Maintaining Security that was signed by then-Foreign Ministers Gareth Evans and Ali Alatas—Indonesia’s first agreement of this kind. It was to prove short-lived, however, being abrogated in 1999 following Australia’s contributions in support of East Timorese independence. This was subsequently replaced with the 2006 Lombok Treaty, but 1995 has traditionally been viewed as a high-water mark of the relationship from an Australian perspective.
Notably, the 1995 and 2026 agreements are almost identical, with the parties agreeing to undertake regular Leader and Ministerial level consultations, develop their cooperation in pursuit of bilateral and regional security, and to “to consult each other in the case of adverse challenges to either Party or to their common security interests and, if appropriate, consider measures which might be taken either individually or jointly and in accordance with the processes of each Party.”
While not an alliance, this language around “consultation” is only found in Article III of the ANZUS Treaty, as well as in Australia’s ‘quasi-alliance’ partnerships with Singapore, Malaysia (as part of the Five Power Defence Arrangements), and Japan. Alongside these states, it clearly positions Indonesia at the highest level of Australia’s strategic partnerships, only behind treaty allies New Zealand, Papua New Guinea and the United States when it comes to mutual obligations and security commitments.
Where to next?
The Jakarta Treaty has the opportunity to exceed the 1995 agreement and is a timely addition and indication of Australia’s strategic priorities—especially in a time of potential rupture in the international order. The challenge nonetheless remains: this is largely a leader-level agreement, dependent on personal goodwill and drive, rather than a more bottom-up and institutionalised framework. It is likely there will need to be considerable diplomatic effort to ensure that a future Indonesian President will be just as invested in this middle power partnership and the virtue of a “common security” approach. Nonetheless, the “common security” lens adopted by the Jakarta Treaty is a welcome reaffirmation of the principles of international law at a time where such principles are being sorely tested.
David M. Andrews 
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