Taking Forward Multilateral Nuclear Disarmament Negotiations

What was the United Nations “Open-Ended Working Group”?

The United Nations first established an Open-Ended Working Group (OEWG) entitled “Taking forward multilateral nuclear disarmament negotiations” in 2012. This UN subsidiary body was characterised by its open and interactive format, making space for deeper participation by members states, experts and civil society organisations.

The first OEWG was mandated by the 2012 UN General Assembly resolution A/RES/67/56 to look at concrete and effective measures, provisions and norms required to eliminate nuclear weapons.

The OEWG began work in the UN in Geneva on 14 March 2013 and was chaired by Ambassador Manuel B. Dengo of Costa Rica. In further sessions from 14-24 May, 27 June, and 19-30 August existing obligations to disarm were reviewed and new pathways for multilateral disarmament explored. The OEWG discussed various approaches to nuclear disarmament, including a step-by-step approach using “building blocks” to reinforce each step, a comprehensive, phased approach within a time-frame, a nuclear weapons convention, and a multilateral legally-binding framework committing states to achieving a nuclear weapons-free world in a defined period of time.

The OEWG reconvened in 2016, after receiving a new mandate from the UN General Assembly in 2015, following the Review Conference of the Non-Proliferation Treaty (NPT) which was unsuccessful at adopting a consensus document, largely due to disagreement on how to move nuclear disarmament forward. In the intervening time, a series of conferences on the Humanitarian Impact of Nuclear Weapons (HINW), hosted by Norway, Mexico and Austria, had taken place. A large group of states had signed up to the Humanitarian Pledge, committing to implement Article VI of the NPT to eliminate nuclear weapons and “to identify and pursue effective measures to fill the legal gap for the prohibition and elimination of nuclear weapons.”

The UN General Assembly resolution A/RES/70/33, mandating the 2016 OEWG, passed in by 135 votes to 12 against, and 34 abstentions. The resolution reaffirmed the “urgency of securing substantive progress in multilateral nuclear disarmament negotiations. The OEWG was tasked to address concrete effective legal measures, including provisions and norms to attain and maintain a world without nuclear weapons. Other measures, such as transparency, risk reduction and measures to increase awareness and understanding of the humanitarian consequences resulting from any nuclear detonation were also to be addressed.

The OEWG took up its work on 22 February 2016, chaired by Ambassador Thani Thongphakdi of Thailand. There were three sessions: 22-26 February, 2-13 May and 5-19 August. The OEWG was open to all member states, international organisations and accredited civil society. None of the nine states that possess nuclear weapons took part in the OEWG. The five recognised Nuclear Weapon States (P5) had voted against establishing an OEWG at the General Assembly, explaining their opposition at the time collectively:

“L.13/Rev.1 [later designated A/RES/70/33] lacks all those vital components that would guarantee meaningful collaboration and a productive outcome as a result of concerted collective effort. This resolution attempts to promote nuclear disarmament whilst ignoring security considerations. We do not believe that such an approach can effectively lead to concrete progress.”

Although the nuclear possessor states were not present, their arguments were put forward during the OEWG by the states allied to them. Concerns were raised about the global security environment, the perceived risk of undermining the NPT, and the need for consensus among all states. A group of 18 states¹ tabled a paper advocating using parallel and mutually reinforcing “building blocks” to create a “progressive approach”, based on the thirteen practical steps to implement Article VI that were adopted at the NPT Review Conference in 2000.

About 103 non-nuclear weapons states took part in the OEWG which were for the most part in favour of a prohibition of nuclear weapons, and were signatories of the “Humanitarian Pledge”. The main thrust of their argument was that the humanitarian consequences and risks associated with nuclear weapons mean that all possible effective measures—both legal and non-legal—should be urgently taken to move away from security policies depending on nuclear deterrence. The “legal gap” (lack of specific prohibition of nuclear weapons) must be overcome to augment the NPT, not undermine it.

The approaches that were identified in the 2013 OEWG were:

1. A comprehensive nuclear weapons convention
2. A stand-alone prohibition treaty
3. A framework agreement, collating various prohibitions and other obligations to disarm and verify.
4. A step-by-step or building block approach where elimination and verification would precede prohibition.

The chair’s draft final report reflected the majority support for the recommendation for the UN General Assembly to mandate negotiations on a prohibition treaty that would lead to total elimination. Australia called for a vote on the final day of the conference because 14 states were not in agreement with the wording “widespread support” for a nuclear ban treaty. After the vote was called for, Guatemala brought in an amendment to the final report.

The amendment meant that paragraph 67 read so:

“The Working Group recommended, with widespread support, the convening, by the General Assembly, of a conference in 2017, open to all States, with the participation and contribution of international organizations and civil society, to negotiate a legally binding instrument to prohibit nuclear weapons, leading towards their total elimination, as outlined in paragraph 34 above.”

The amendment passed and the amended report was adopted by 68 to 22, with 13 abstentions. However, the states allied to the Nuclear Weapons States were not content with this result and the following was added:

“The Working Group recognized that other states² did not agree with the above recommendation and that they had recommended that any process to take forward multilateral nuclear disarmament negotiations must address national, internationale and collective security concerns and supported the pursuit of practical steps, consisting of parallel and simultaneous effective legal and non-legal measures to take forward multilateral nuclear disarmament negotiations.”

Despite the contentiousness over which approach was the correct one to recommend, the rest of the discussions during the 2016 OEWG were seen to be constructive. Other issues, such as transparency measures, risk reduction and raising awareness on the humanitarian consequences, were covered well. Concerns over modernisation of nuclear weapons or prevention of nuclear terrorism were also included in the final report.

The recommendation of the 2016 OEWG resulted in UN General Assembly resolution A/RES/71/258 which passed on 23 December 2016. 113 states were in favour, 35 against and 13 abstained. The negotiations took place in 2017 and the treaty was adopted on 7 July 2017. The treaty entered into force on 22 Jan 2021. To date it has been signed by 95 states and 75 states have ratified membership.

Verbatim:

UN General Assembly: Taking forward multilateral nuclear disarmament negotiations, A/RES/67/56, 3 Dec 2012

Final Report of the Open-Ended Working Group to develop proposals to take forward multilateral nuclear disarmament negotiations for the achievement and maintenance of a world without nuclear weapons, A/68/514, 9 Oct 2013.  

UN General Assembly:Taking forward multilateral nuclear disarmament negotiations, A/RES/70/33, 7 Dec 2015  

Guitton, Amb. A: Explanation of vote on behalf of People’s Republic of China, the Russian Federation, the United Kingdom of Great Britain and Northern Ireland, the United States of America and France, 2 Nov 2015 

Final Report of the Open-Ended Working Group taking forward multilateral nuclear disarmament negotiations, A/71/371, 1 Sep 2016  

Further Reading:

Hall X: Ten years on: History in the making, IPPNW Peace and Health Blog, 19 Aug 2026  

Nielsen J: 2016 Open-ended Working Group: Towards 2017 nuclear weapon ban negotiations? Arms Control Wonk, 13.09.2016

UNIDIR: Taking Forward Multilateral Nuclear Disarmament Negotiations: The 2016 Open-Ended Working Group, UNIDIR Resources, 11 Oct 2016 https://unidir.org/wp-content/uploads/2023/05/the-2016-open-ended-working-group-en-660.pdf 

All working papers from states, NGOs and other organisations, presented at the 2016 OEWG, can be found in the list of documents published on the Reaching Critical Will website.

1. Australia, Belgium, Bulgaria, Canada, Estonia, Finland, Germany, Hungary, Italy, Japan, Latvia, Lithuania, Netherlands, Poland, Portugal, Romania, Slovakia and Spain. ↩︎
2. States supporting this recommendation comprise, inter alia, the 24 States advocating the
   progressive approach: Australia, Belgium, Bulgaria, Canada, Croatia, Czech Republic, Estonia, Finland, Georgia, Germany, Greece, Hungary, Italy, Japan, Latvia, Lithuania, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, and Spain. ↩︎