In this final episode of the series, attention returns to how nuclear responsibilities are talked about, with particular emphasis on the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and its review cycle. In the episode, Dr Megan Dee and Dr David Chambers (Head of the Arms Control and Disarmament Research Unit, Foreign, Commonwealth and Development Office, United Kingdom) discuss the different framings and approaches that can be used – and avoided – by States when talking nuclear responsibilities in an NPT framework, as well as the merits of using a nuclear responsibilities approach to strengthen dialogue and contribute to transparency, confidence-building, and risk reduction efforts.

From medicine to food and power, nuclear technologies produce multiple benefits for individuals in their day-to-day lives and are playing an increasingly crucial role in delivering the UN Sustainable Development Goals. Under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), States Parties have a sovereign right to the peaceful uses of nuclear energy. That right nevertheless comes with responsibilities, particularly for nuclear supplier states, but also for civic nuclear programmes and their respective regulators. In this episode, Dr Megan Dee and Ingrid Kirsten (Senior Fellow, Vienna Center for Disarmament and Non-Proliferation) explore the responsibilities associated with the peaceful uses of nuclear energy, reflecting on how responsibilities are attributed – and upheld - to ensure that nuclear materials and technologies not only remain safe and secure but also accessible to those most in need.

The international nuclear non-proliferation regime is coming under increasing strain in this new nuclear age. Vertical proliferation concerns are rife as the nuclear possessor states modernise their nuclear arsenals while signalling the possibility of a return to nuclear testing. Horizonal nuclear proliferation concerns now centre not only on "rogue states" and non-state actors, but also the domestic debates of long-established non-nuclear weapon states signalling potential interest in developing nuclear arsenals. In this episode, Dr Megan Dee and Dr Toby Dalton explore nuclear responsibilities as they relate to nuclear non-proliferation, along with the challenges this third nuclear age presents for the non-proliferation regime at large.

For non-nuclear weapon states, nuclear disarmament is considered both the primary and special responsibility of the nuclear-weapons states and particularly the P5 signatories to the Non-Proliferation Treaty (NPT). Yet in a nuclear age where the nuclear-weapons states seek to advance and modernise their nuclear arsenals, pursue technological development, and even signal the return of nuclear testing, where does this leave disarmament as a nuclear responsibility? In this episode, Dr Megan Dee and Maria Antonieta Jaquez consider nuclear responsibilities and the topic of nuclear disarmament, looking at the different perspectives surrounding this debate, including as it relates to the disarmament principles of irreversibility, transparency and verification.

Nuclear responsibilities can be associated with a variety of norms, practices, and state behaviours that have been generated, diffused, and institutionalised since the first nuclear age commenced in 1945. In this episode, Dr Megan Dee and Dr Ben Zala consider how nuclear responsibilities have evolved over the first and second nuclear ages. They reflect on how nuclear responsibilities have also been questioned, critiqued, and potentially undermined in this new nuclear age and the challenges – and opportunities – this poses, particularly in multilateral forums such as the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) review process.

What are nuclear responsibilities and why do they matter? In this opening episode, Dr Megan Dee and Dr Alice Spilman introduce nuclear responsibilities as a prevalent theme and loaded term within contemporary global nuclear politics and diplomacy. The episode introduces the different ways in which nuclear responsibilities have been talked about in global nuclear weapons politics and diplomacy, and the challenges and opportunities this presents.