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Guest Column

ASEAN's admission of Timor-Leste has bypassed Charter-mandated procedures, relying instead on a political Roadmap that creates asymmetries in members' rights and obligations. A formal, Charter-based accession procedure is essential to preserve ASEAN's rules-based identity and ensure legal coherence in future enlargements.

ASEAN’s recent decisions in Kuala Lumpur to admit Timor-Leste as its eleventh member on 26 October 2025, alongside Timor-Leste’s accession to the ASEAN Charter and the Treaty on the Southeast Asia Nuclear-Weapon-Free Zone (SEANWFZ), have created a confusing legal process for a complex undertaking. Membership is not ceremonial; it entails binding obligations under approximately 400 legal instruments. To protect ASEAN’s rules-based identity and establish sound precedent, the process should be grounded in the ASEAN Charter and conducted through the organs and procedures it prescribes. This essay argues that the Charter-based accession procedure is essential to address and prevent ongoing imbalances in rights and obligations between Timor-Leste and other ASEAN Member States.

Charter Requirements and the Limits of Political Roadmaps

The ASEAN Charter assigns clear institutional responsibilities for the admission of new members. Article 6(1) requires the ASEAN Coordinating Council (ACC) to prescribe a procedure for the application and admission of new members. That procedure should guide application processes, structure negotiations, and clarify how accession interfaces with ASEAN’s broader legal architecture.

Since the Charter entered into force, however, the ACC has not established, or at least not published, such a procedure. Proceeding without one risks confusion and undermines legal certainty. Assuming no formal accession procedure has been issued or published, the Roadmap adopted in 2023 remains the only guideline for Timor-Leste’s accession. The Roadmap and its annexes are political instruments; they set out expectations rather than a legally grounded process and include accession to terminated legal instruments among the Roadmap milestones, thereby blurring the line between political priorities and legal requirements. Replacing the Charter-mandated procedure with the Roadmap to guide Timor-Leste’s admission process is procedurally problematic. The current process departs from the Charter’s mandate under Article 6(1) and sets a poor precedent for post-Charter admissions, normalising ad hoc shortcuts that erode legal certainty.

Addressing Accession Asymmetries: A Rules-Based Pathway for ASEAN Membership

Articles 1 and 2 of the ASEAN Charter set out ASEAN’s purposes and principles. To realise these aims, ASEAN Member States have concluded more than 200 ASEAN legal instruments among themselves. All ten ASEAN Member States participate in these legal instruments through signature and, where applicable, ratification, acceptance, approval, or accession. Under ASEAN practice, it is customary for all ASEAN Member States to participate in all ASEAN legal instruments. When its membership was confirmed on October 26, 2025, Timor-Leste had acceded only to the ASEAN Charter, the Treaty of Amity and Cooperation in Southeast Asia (TAC), and the Treaty on the Southeast Asia Nuclear-Weapon-Free Zone (SEANWFZ). This made Timor-Leste the only Member State that did not participate in a majority of ASEAN legal instruments at the time of its confirmation as the eleventh Member State.

With this limited accession profile, imbalances in rights and obligations have arisen between Timor-Leste and other Member States. For example, Timor-Leste now participates in ASEAN organs under the Charter, such as participating in ASEAN Sectoral Ministerial Bodies under the ASEAN Economic Community (AEC). However, it has yet to assume the corresponding treaty obligations under such Community legal instruments, which creates asymmetries in market-access rights and compliance duties. These circumstances create tension with the Charter’s aspiration of practical equality and raise questions about ASEAN’s credibility as a rules-based organisation. These asymmetries underscore the need for a standardised, Charter-grounded accession pathway.

Ideally, the ACC should prescribe an accession procedure that enables timely accession to core legal instruments and facilitates the prompt deposit of instruments of accession by the acceding state to at least some core agreements, for example all ASEAN Political-Security Community and ASEAN Socio-Cultural Community legal instruments, as well as fundamental AEC treaties such as the ASEAN Trade in Goods Agreement (ATIGA), the ASEAN Trade in Services Agreement (ATISA), the ASEAN Comprehensive Investment Agreement (ACIA), and the ASEAN Framework Agreement on the Facilitation of Goods in Transit (AFAFGIT), and, finally, the Charter. Consistent with Article 6(4) of the ASEAN Charter, accession to the Charter is positioned last to serve as the formal act that effects admission to ASEAN. This should then be followed by clear transitional implementation and monitoring mechanisms, including a timeline for accession to the remaining legal instruments. This approach preserves legal coherence, accelerates reciprocal market-access benefits, and minimises imbalances in rights and obligations after admission, while ensuring that domestic legislation, institutions, and systems are ready to implement the new commitments.

Timor-Leste and External Legal Instruments

In addition to instruments concluded among ASEAN Member States, ASEAN and its Member States have concluded more than 200 legal instruments with external partners, the majority of which are free trade agreements and cooperation agreements. In the absence of an accession procedure, clarification is needed on Timor-Leste’s status in relation to these instruments. Specifically: (i) whether, under Article 5(1) of the ASEAN Charter, Timor-Leste’s membership requires accession to all of these instruments; (ii) the applicable procedures for Timor-Leste to accede; and (iii) the timelines for such accession. Providing these clarifications would ensure legal certainty and coherence in Timor-Leste’s integration into ASEAN’s external legal framework.

Conclusion

In conclusion, the ACC should prescribe the accession procedure and clarify the sequencing across core internal legal instruments and relevant external agreements. Consistent with Article 6(4) of the ASEAN Charter, accession to the Charter should serve as the capstone act affecting admission, following timely accession to core agreements and accompanied by transitional implementation and monitoring mechanisms. This approach would provide Timor-Leste with a clear, lawful pathway to full participation and bolster the legitimacy, predictability, and effectiveness of ASEAN enlargement. By contrast, proceeding based on limited accessions to the Charter, TAC, and SEANWFZ, without an ACC-led procedure and with reliance on the Roadmap, risks sustained imbalances in rights and obligations and weakens confidence in ASEAN’s rules-based system. Clarifying Timor-Leste’s status in relation to ASEAN’s external legal instruments, including scope, procedures, timelines, and sequencing, will further ensure legal certainty and coherence in its integration with ASEAN’s broader legal architecture.

 

 

Johan Pahlepi is a Research Associate at the Centre for International Law, National University of Singapore.

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The views expressed in the article are solely those of the author(s) and do not necessarily reflect the position or policy of the Lee Kuan Yew School of Public Policy or the National University of Singapore.

Image Credit:  Flickr/Charles Wiriawan, CC BY-NC-ND 2.0

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