The Treaty on the Southeast Asia Nuclear Weapon-Free Zone, also known as the SEANWFZ Treaty or Bangkok Treaty, was signed on 15 December 1995 by ten Southeast Asian States. The Treaty, which entered into force on 27 March 1997, was registered with the United Nations on 27 June 1997. The Treaty established the world’s third Nuclear Weapon-Free Zone (NWFZ).

The SEANWFZ Treaty includes a few elements that go beyond other existing NWFZ agreements. First, the zone of application goes beyond the territorial seas to include the continental shelves and the exclusive economic zones (EEZ) of the contracting parties. Second, the negative security assurances protocol implies a commitment by the nuclear-weapon States (NWS) not to use nuclear weapons against any contracting State or protocol party within the zone of application. Notably, none of the NWS have signed or ratified the negative security assurance protocol. Third, the Treaty stipulates that in the case of a breach of protocol (i.e. the use or threat of use of nuclear weapons), the Executive Committee of the Treaty will convene in a special meeting to decide on appropriate actions.

The Treaty obliges States Parties not to develop, manufacture, or otherwise acquire, possess, or have control over nuclear weapons, station or transport nuclear weapons, or test or use nuclear weapons. States Parties also undertake not to discharge radioactive material or wastes at sea, into the atmosphere, or on land within the Zone, and not to allow other States to conduct these acts.

The Treaty requires all parties to apply full-scope International Atomic Energy Agency safeguards to all their peaceful nuclear activities.

The SEANWFZ Commission, comprised of the ASEAN Foreign Ministers, oversees the implementation of the Treaty and ensures compliance with its provisions. The Commission is assisted by the SEANWFZ Executive Committee and its Working Group. Issues related to the NWFZ are discussed during the ASEAN Summits. The Executive Committee of the Commission is composed of the representatives of all member States. The Committee is tasked primarily with verification- and compliance-related matters as well as “other tasks” assigned by the Commission. SEANWFZ States have also established a special Working Group of the Executive Committee to advance the Treaty’s protocol signature.

The protocol asks of NWS to respect the Treaty and not to contribute to any act, which constitutes a violation of the Treaty or its protocol by States Parties. They also include an undertaking not to use or threaten to use nuclear weapons against any State Party to the Treaty and not to use or threaten to use nuclear weapons within the SEANWFZ.

For the full text Treaty, see here.

Membership

The current States Parties to the Treaty are: Brunei Darussalam, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Timor-Leste, Thailand, and Viet Nam. For information on accession dates, see here.