The Southeast Asian Nuclear-Weapon-Free Zone Treaty (SEANWFZ) is a nuclear weapons moratorium treaty between 11 Southeast Asian member-states under the auspices of ASEAN: Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, Vietnam and Timor-Leste.
The Southeast Asian Nuclear Weapon-Free Zone Treaty (SEANWFZ), also known as the Bangkok Treaty (1995), has emerged at the forefront of disarmament debates in Southeast Asia following China’s July 3, 2025, announcement of its willingness to join the treaty.
The subsequent statement by Malaysia’s Foreign Minister Mohamad Hasan on July 10, 2025, reaffirmed Beijing’s commitment to sign the treaty without reservation. The SEANWFZ Treaty serves as a cornerstone of ASEAN’s mandate to preserve Southeast Asia as a nuclear-weapon-free zone, extending to the prohibition of other weapons of mass destruction (WMD).
Over the years, ASEAN member states have consistently urged the five recognised nuclear-weapon states (P5) to accede to the treaty’s protocol, which would strengthen the global nuclear non-proliferation regime and enhance the credibility of Southeast Asia’s security structure, potentially creating a win-win framework for both regional and global stability. In the 21st century, with the Doomsday clock set at 89 seconds to midnight (as of August 2025), China’s decision to join the SEANWFZ Treaty reflects a quest for regional resistance against the growing nuclear anxieties between nuclear-weapon states. Does this rhetorical step towards disarmament have any calculated self-interest intertwined with broader regional strategy? This is a critical point of anticipation.
China’s willingness to join as a signatory provides it with an opportunity to establish Beijing as a responsible stakeholder in the contemporary security framework amid the increasing frictions between the great powers. This decision paves the way for China to represent itself as a champion of disarmament, first among the P5 states, thereby leveraging the hesitancy of the United States and Russia to accede to the treaty. Beijing will likely reconstruct the framework of the SEANWFZ Treaty, stepping up into a leadership position & playing a greater role in being an implementation force in the Southeast. With its considerable financial magnitude and diplomatic outreach, China is well placed to facilitate the treaty’s functionality and visibility on the global stage. It may further place ASEAN’s collective vision into jeopardy, becoming influenced by China’s dominating role.
China’s leading patron narrative will help the state deepen its alliance with ASEAN, unlocking various strategic advantages. First, it can strengthen trade diplomacy, with ASEAN already accounting for 1.71 trillion yuan (US$234 billion), or 16.6% of China’s total foreign trade in the first quarter of 2025. Further, the intensified bilateral relations with ASEAN will facilitate China’s Belt and Road (BRI) initiative, as states – Myanmar, Laos, Thailand, and Cambodia, along with proximate states like Vietnam and the Philippines are of critical importance for overland connectivity projects and China’s maritime initiatives. Finally, the maritime initiatives include the South China Sea dispute, which will remain of critical importance. The negotiations post China being a signatory of the SEANWFZ Treaty will be instrumental in shaping whether the treaty will become a platform for easing tensions or a mere tool for bargaining power politics, consolidating China’s underlying objectives.
China’s commitment to the SEANWFZ Treaty can also be viewed through the lens of operational practices that it might engage in through its civil nuclear industry. The China National Nuclear Corporation (CNNC) and China General Nuclear Power Group (CGN) are a pivotal part of their nuclear diplomacy. The Chinese nuclear export control regimes are governed by regulations like Regulations on Control of Nuclear Dual-Use Items and Related Technologies Export (1998, revised 2007), which align closely with NPT frameworks, IAEA safeguards, and Nuclear Supplier Group (NSG) guidelines.
By bringing such regulations into force, Beijing has potentially laid the ground for becoming a responsible nuclear supplier by advocating for the peaceful use of nuclear technology. Being a signatory of the SEANWFZ Treaty will boost the Chinese market, which has long struggled to find potential buyers due to protracted construction time and limited business model innovations. Amid such fragile nuclear market influence, the ambition of ASEAN states (mainly Vietnam, Indonesia, and the Philippines) to become civil-nuclear states by 2030 – 2035 has provided China with a renewed opportunity to place itself as a competitive supplier. This confluence between ASEAN’s civil-nuclear aspirations and China’s market vulnerability creates a mutually reinforcing dynamic. The SEANWFZ Treaty umbrella will establish China as an economically beneficial partner and legitimise its position as a primary supplier for ASEAN’s aspiring civil-nuclear market.
Whether China’s involvement will mark a milestone in the history of the SEANWFZ Treaty will depend on how well the treaty can manage its credibility and preservation of centrality in the Southeast Asia region. The complexities arise if one puts the unresolved maritime disputes at the core of the SEANWFZ treaty, specifically pertaining to China. China’s interpretation of the Exclusive Economic Zone (EEZ) overlaps with those of ASEAN member states like the Philippines, Malaysia, and Vietnam. As the SEANWFZ Treaty prohibits developing, manufacturing, acquiring, possessing, stationing, testing, or using nuclear weapons anywhere within the treaty zone, which covers territories, continental shelves, and EEZs, the overlapping maritime claim creates dilemmas for the treaty’s credibility, if signed by China. If China implements the treaty selectively and leaves out the contested waters, it might further lead to critical implications, bringing accountability against the backdrop of the treaty’s framework. The fault in demarcations will create a challenging environment for the verification and compliance mechanisms of the treaty.
China’s accession to the SEANWFZ Treaty is a well-calculated action, adding to the rhetoric of responsible regional power behaviour. Whether it is a mere discourse or a substantive step restructuring China’s strategic and nuclear posture, it will further depend on how willingness translates into concrete commitments. The extent to which actions are implemented, justify the means and ends to the objective of the treaty, will be a topic of evaluative importance.
Title Image Courtesy: https://www.thevietnamese.org/2025
Disclaimer: The views and opinions expressed by the author do not necessarily reflect the views of the Government of India and the Defence Research and Studies
References
https://www.globaltimes.cn/page/202504/1332056.shtml
http://eng.mod.gov.cn/xb/Publications/LR/4888370.html,
https://www.cfr.org/global-conflict-tracker/conflict/territorial-disputes-south-china-sea
https://www.sciencedirect.com/science/article/pii/S2214629623002906
https://www.nuclearbusiness-platform.com/media/insights/asean-goes-nuclear
