Pugwash Meeting on Irreversibility in the Nuclear Domain

British and International Pugwash convened a discussion on the theme of irreversibility in the nuclear domain in Rome on 20 and 21 November 2023. The 12 participants, present in a personal capacity, came from the USA, Russia, China, India, the UK, Canada, Italy, Belgium, and Germany. The group comprised former diplomats, political scientists, physicists, and a nuclear weapon engineer.

Recognising that various research centres and academic institutions had already done much work on irreversibility in the nuclear domain, including verification of nuclear weapon elimination, the meeting sought to add value by identifying how nuclear possessor states might move from currently prevailing conditions to a world free of nuclear weapons in as irreversible a way as possible, it being understood that resilience could be a more realistic objective than absolute irreversibility.

Participants were conscious of, and deplored, a serious deterioration in the outlook for nuclear disarmament in recent years. Recalling a 2023 G20 affirmation that “the use or threat of use of nuclear weapons is inadmissible”, they strove to generate ideas that could make the use of nuclear weapon not only inadmissible but also unthinkable. They succeeded in identifying significant practical steps that the nuclear possessor states could take towards nuclear weapon elimination. Such steps would better serve the security interests of possessor states, it seemed to the meeting, than continuing to tolerate the level of risk that is inherent in the status quo.

The discussion focussed largely on the negotiation of the Chemical Weapons Convention (CWC) and the elimination of chemical weapons to which it led. It proved possible to draw lessons from that negotiation which could be applied to the elimination of nuclear weapons. Participants noted that the resilience sought by CWC negotiators was of a broad political nature and that it had been achieved by generating confidence in the adequacy of verification arrangements and in all parties’ commitment to the goal of elimination.

A presentation on external verification of the then South African government’s decision to eliminate the nuclear weapons it acquired during the 1980s, and to accede to the Nuclear Non-Proliferation Treaty, proved to be rich in lessons that could be applied to verifying a more general elimination of nuclear weapons. The meeting noted with special interest that South African military leaders of that period appeared to have placed little or no value on the possession of nuclear weapons; the weapon programme had been driven forward by nuclear engineers and politicians.

A summary of the discussions has been presented to the Foreign, Commonwealth and Development Office, and it is hoped that they will make it available to the other four Nuclear Weapon States, with whom UK representatives meet regularly.