In 2025, the world commemorates solemn milestones. It is 80 years since the first nuclear test and the atomic bombings of Hiroshima and Nagasaki, as well as the 15th International Day against Nuclear Tests. As global tensions rise, Maren Vieluf underscores the importance of defending the test ban to safeguard the global nuclear order
In November 2023, Russian President Vladimir Putin 'de-ratified' the Comprehensive Test Ban Treaty (CTBT). His decision reflects a broader trend of nuclear brinkmanship, including threats to use nuclear weapons, attacks on nuclear power plants, and obstruction of arms control and non-proliferation negotiations. In an era already marked by loose nuclear rhetoric, a return to nuclear testing would undermine the global nuclear order. It would show blatant disregard for the very norms and agreements that have been instrumental in preventing nuclear conflict.
Some policymakers may argue that a test by an established nuclear power poses little risk to global stability. This dangerously underestimates the cascading effects. Breaking the testing taboo risks normalising escalation, weakening long-standing norms, and raising the risk of renewed arms races, proliferation, or even nuclear use.
The nuclear order balances inherently contradictory goals: deterrence, arms control, non-proliferation, and disarmament. Despite longstanding aspirations for 'global zero', the world is still grappling with the legacy of the 1945 nuclear attacks on Hiroshima and Nagasaki, the impacts of 2,056 nuclear weapons tests, and the reality of more than 12,000 nuclear weapons currently possessed by nine states. The nuclear order calls for restraint, yet relies on a logic of deterrence. While nuclear-armed states seek to maintain nuclear weapons solely within their control, many non-nuclear-armed states advocate for universal disarmament.
While nuclear-armed states seek to maintain nuclear weapons solely within their control, many non-nuclear-armed states advocate for universal disarmament
Nuclear tests – controlled explosions of nuclear weapons or their components – serve technological and political purposes. Governments use them to advance nuclear weapons design, safety, and impact assessments, and to demonstrate strength and capability through nuclear signalling, reinforcing deterrence.
Technological advances have rendered nuclear testing obsolete. Any new test would be a deliberate and purely political act – whether conducted by an existing nuclear-armed state or a potential new member of the 'nuclear club'. North Korea remains the only country to have conducted nuclear tests since the 1990s, and must not serve as a model for others.
Technological advances have rendered nuclear testing obsolete. Any new test would be a deliberate and purely political act
Nuclear testing has a historical legacy deeply intertwined with colonialism, racism, and oppression. States have typically conducted nuclear tests in remote areas, disproportionately affecting Indigenous and marginalised communities. These tests have caused, and continue to cause, profound harm to people and the environment, and affected communities continue to call for full acknowledgement and redress of these impacts.
Early treaties, such as the 1963 Partial Test Ban Treaty, limited atmospheric testing but lacked verification measures, allowing for non-compliance. Regional nuclear-weapon-free zones, such as the 1967 Treaty of Tlatelolco, have proven effective. A global ban, however, has yet to materialise.
The preamble to the 1968 Non-Proliferation Treaty (NPT) committed member states to working towards the cessation of nuclear testing. This goal was later advanced by the 1996 CTBT. Despite 187 states signing and 177 ratifying the CTBT, it has not yet entered into force. The refusal of key Annex 2 states – including the nuclear-armed United States, China, India, Israel, North Korea, Pakistan, and now Russia – to ratify the CTBT undermines not only the treaty itself but the broader credibility of nuclear non-proliferation efforts. The CTBT’s International Monitoring System plays an important role in detecting violations, but enforcement of the treaty remains elusive.
Norms, defined as shared expectations of behaviour, evolve over time and through challenges. Their interconnectedness, however, means that a single violation could unravel the entire normative framework if it becomes part of a broader pattern of non-compliance. Given the destructive potential of nuclear weapons, any preparation for their use, including testing, calls for the utmost caution.
Given the destructive potential of nuclear weapons, any preparation for their use, including testing, calls for the utmost caution
Even without overt violations, states contribute to the erosion of the nuclear order through subtle, habitual actions that contradict its core principles. By keeping test sites operational, conducting nuclear-capable missile tests, and holding military exercises, as well as through modernisation and quantitative armament efforts, nuclear-armed states undermine norms while portraying themselves as responsible actors. Some non-nuclear-armed states maintain 'nuclear latency' – the capability to develop nuclear weapons – by retaining nuclear infrastructure and materials. Some states invoke strategic discussions or threats of proliferation as part of their hedging strategies. Recent developments have also sparked renewed debates around extended nuclear deterrence arrangements in light of the evolving acquis of the 1970 NPT.
These practices reshape perceptions of the purpose and interpretation of the existing norms in a way that a majority of states do not share, thereby widening the ideological divide.
There is ample room for improvement within the nuclear order, but its core tenets – that nuclear weapons will neither be tested, proliferated, nor used – must remain inviolable. Deviations risk weakening the moral and legal foundations of a system designed to safeguard global peace and security.
The renewed debate over nuclear testing presents a profound challenge to the international order. As geopolitical tensions rise, reaffirming the norm against testing is essential to safeguard global security. Amid potential nuclear escalation, some may dismiss reliance on nuclear weapons prohibition norms as naïve. Yet, these norms have helped prevent nuclear conflict. Because they are interlinked, the erosion of one threatens the integrity of all; defending one, in turn, reinforces the whole.
Now, more than ever, states must condemn any plans to resume nuclear testing and urgently pursue ratification and universalisation of the CTBT. The future of nuclear restraint – and the possibility of disarmament – depends on it.
☢️ No.13 in a Loop series on the Nuclear Politics Paradox
The views expressed are those of the author, and do not reflect the position of the German Federal Foreign Office
