1. Introduction

The discussion highlights the significance of nuclear-weapon-free zones in global non-proliferation and disarmament efforts, particularly the establishment and development of the Southeast Asia Nuclear-Weapon-Free Zone (SEANWFZ). Since the end of the Cold War, heightened international awareness of nuclear risks and the growing autonomy of regional states in pursuing peace and security have driven the creation of multiple nuclear-weapon-free zones. The Treaty on the Southeast Asia Nuclear-Weapon-Free Zone (Bangkok Treaty), signed in 1995 and entering into force in 1997, covers the land territories, continental shelves, and exclusive economic zones of ten Southeast Asian countries. It aims to eliminate the possibility of nuclear weapons in the region and create a secure environment free from nuclear threats and disasters. Academic research on SEANWFZ has primarily focused on the motivations, operational models, and impacts of this unique regional nuclear control mechanism. However, there remains a lack of systematic and coherent diachronic analysis of the treaty's 30-year trajectory, as well as a tendency toward fragmented or singular analytical perspectives. In 2025, the SEANWFZ Treaty once again became a focal point of international attention. Chinese Foreign Minister Wang Yi reiterated China's steadfast support for the establishment of SEANWFZ and expressed willingness to sign the treaty's protocol. This stance contrasts sharply with that of the United States, where successive administrations have delayed signing the protocol under various pretexts, effectively creating insurmountable political obstacles to the treaty's full implementation. The development of SEANWFZ relies on the support of the United Nations-centered multilateral governance framework. Yet, the complex challenges it faces also reflect the broader dilemmas confronting global governance and multilateralism today.

2. Motivations and Evolution of SEANWFZ: From Concept to Reality

The motivations and evolution of SEANWFZ reveal how regional states pursued security, autonomy, and identity under specific historical conditions. The concept originated during the Cold War, when Southeast Asian nations sought mechanisms to safeguard themselves from external nuclear threats and avoid entanglement in nuclear confrontations. As a regional organization, ASEAN leveraged the establishment of SEANWFZ to bolster its institutional framework and legitimacy in security governance. Valuing their independent status, Southeast Asian countries framed SEANWFZ as a concrete legal manifestation of the "Zone of Peace, Freedom, and Neutrality" (ZOPFAN) doctrine—a symbol of collective identity and the right to autonomously determine regional security. In 1971, five ASEAN members adopted the ZOPFAN Declaration, laying the political and conceptual groundwork for SEANWFZ. Throughout the 1970s and 1980s, ASEAN deliberated on pathways to realize ZOPFAN, gradually clarifying the vision for a nuclear-weapon-free zone. In 1984, ASEAN designated SEANWFZ as a key step toward ZOPFAN and established a working group to draft and negotiate the treaty. Negotiations centered on defining geographic scope and rights to peaceful nuclear energy. The final compromise explicitly applied the treaty to member states' territories, territorial seas, continental shelves, exclusive economic zones, and airspace. It obligated parties to prohibit the development, manufacture, acquisition, possession, control, deployment, testing, use, or threat of use of nuclear weapons, while instituting a verification system based on IAEA safeguards. ASEAN also adopted an additional protocol calling for negative security assurances from nuclear-weapon states. Signed at the 5th ASEAN Summit in 1995 and entering into force in 1997, the SEANWFZ Treaty marked a critical milestone in regional collaborative security governance.

3. Achievements and Challenges of SEANWFZ

Over its 30-year existence, the SEANWFZ Treaty has witnessed profound changes in Southeast Asia's economic, political, and geopolitical landscape. While it has succeeded in cementing the region's nuclear-weapon-free status, its full objectives remain unrealized amid mounting internal and external pressures. All ten ASEAN members have joined the treaty, enshrining its obligations in domestic laws to permanently affirm their non-nuclear status. The treaty guarantees rights to peaceful nuclear energy, though civilian nuclear programs in some states have progressed slowly. All parties maintain comprehensive IAEA safeguards agreements, with no reported violations of nuclear weapons activities. However, the treaty's Executive Committee functions merely as a political consultation platform, lacking an independent secretariat or robust technical verification capacity.

SEANWFZ confronts challenges including intensifying geopolitical rivalries, institutional weaknesses, and eroding normative consensus. The absence of recognition from nuclear-armed powers undermines the zone's legitimacy. The U.S. and other Western nuclear states refuse to sign the protocol, citing concerns over restrictions to naval and aerial mobility in exclusive economic zones, potential erosion of extended nuclear deterrence credibility, and ambiguities in treaty definitions regarding maritime zones. Conditional "negative security assurances" remain another point of contention. Without legally binding recognition and security guarantees from nuclear-armed states, SEANWFZ's authority faces fundamental skepticism.

Internal institutional deficiencies manifest in three areas: verification and monitoring capabilities, executive authority, and sustained resource allocation. The treaty's verification mechanism remains fragile, over-relying on IAEA safeguards while lacking independent, professional, and proactive inspection capacities. The Executive Committee's authority and operational effectiveness are constrained, limited mostly to procedural reviews, information exchange, and superficial policy discussions. Fluctuating commitment and resource investments from ASEAN members further weaken institutional efficacy.

Eroding normative consensus increasingly undermines SEANWFZ's moral foundation and international credibility, stemming from nuclear powers' "double standards," inefficiencies in regional decision-making, and latent risks associated with civilian nuclear technology. Inconsistent behavior by nuclear-armed states constitutes the primary factor weakening the zone's normative authority. The inherent inefficiencies of the "ASEAN Way" hinder collective action on sensitive issues. Meanwhile, dual-use risks from civilian nuclear programs pose long-term challenges to the zone's integrity.

The convergence of non-traditional security threats and disruptive emerging technologies presents SEANWFZ with challenges beyond traditional "nuclear-free" frameworks, testing its adaptability and enforcement. Southeast Asia's vulnerability to natural disasters—earthquakes, tsunamis, typhoons, and floods—exacerbated by climate change, complicates nuclear safety. As a global trade and shipping hub, the region faces tangible risks of illicit trafficking in nuclear and radioactive materials. Uneven physical protection standards for research reactors, medical radiation sources, and other critical infrastructure—particularly against cyber threats—create security gaps. Emerging technologies like hypersonic weapons, cyber warfare, space militarization, and AI-integrated military systems are profoundly reshaping strategic stability, demanding unprecedented adaptations from traditional arms control frameworks including SEANWFZ.

4. The Future of SEANWFZ: Trends and Potential Pathways

While the SEANWFZ Treaty has succeeded in maintaining the region's nuclear-weapon-free status, geopolitical, institutional, and normative challenges persist. Four potential pathways are proposed: First, adjusting strategic expectations and enhancing crisis resilience through sub-issue breakthroughs (e.g., nuclear security hotlines, joint radioactive waste management projects) and strategies to manage AUKUS-related disruptions. Second, deepening institutional reforms to modernize implementation capabilities—transcending the "ASEAN Way," strengthening treaty enforcement, shifting from passive compliance to active norm-shaping, expanding from arms control to comprehensive security, and broadening elite consensus into societal foundations. Third, expanding cooperative networks to amplify normative influence by deepening IAEA collaboration, promoting Additional Protocol adoption, establishing regional nuclear security training centers, and strengthening ties with other nuclear-free zones. Fourth, proactively addressing disruptive technological challenges through regional dialogues on "emerging technologies and strategic stability," clarifying key concepts and risk perceptions, and building technical confidence-building measures to reduce miscalculation risks.

5. Conclusion

The 30-year journey of SEANWFZ underscores its core achievements in establishing regional nuclear-free identity and preserving peace, while exposing structural dilemmas—great power rivalries, institutional weaknesses, and eroding normative foundations. Its future will likely follow a challenging "rocky middle path," yet its core value remains irreplaceable. Southeast Asia's experience offers critical lessons for global nuclear security governance: regional mechanisms are indispensable pillars; normative power requires material backing; and humanity's hope in managing existential threats lies in multidimensional innovations integrating material, institutional, and ideational approaches. Whether Southeast Asian nations can preserve this nuclear-free sanctuary will determine not only regional peace but also test humanity's capacity to govern ultimate security threats.