According to the official UN website, nearly three decades ago, the world took decisive steps to bring nuclear test explosions to an end. Those actions changed the course of history. Where once the ground shook with alarming regularity, today such events are rare, a testament to the strength of our collective resolve. On 29 August, the International Day against Nuclear Tests (IDANT), we reaffirm our commitment to placing non-proliferation and disarmament first, and to ensuring that no person ever again lives in the shadow of a nuclear explosion.I will never forget standing at ground zero in Semipalatinsk, Kazakhstan – a site scarred by more than 450 nuclear tests – the closure of which we also commemorate on this day. I felt the full weight of that history, a sobering reminder of what the international community must never allow to happen again.
At the height of the cold war, such tests occurred almost weekly. They were not only a grave risk to global peace and security but also had a lasting impact on public health and the environment.
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) was opened for signature in 1996 after years of determined multilateral effort. It reflected the combined strength of diplomatic will and scientific progress. By prohibiting nuclear test explosions conducted by anyone, anywhere, at any time, the Treaty transformed decades of aspiration into a shared commitment. It signalled that the world’s nations were ready to turn a historic page.
From over 2,000 tests to fewer than a dozen
Before CTBT was opened for signature, more than 2,000 nuclear test explosions had been conducted worldwide. Since 1996, that number has fallen to fewer than a dozen. This dramatic decline is no accident. It reflects the strength of the norm created by our Treaty and the value that the international community places on preventing any return to testing.
The Treaty is already a proven success. It has brought almost all nuclear testing to an end, placing powerful constraints on the development of new nuclear weapons and the advancement of existing designs, while fostering a strong international expectation that testing belongs in the past. Entry into force will build upon this, giving us the full range of verification measures, including on-site inspections, to further reinforce what has already been achieved.
The power of verification
The success of the Treaty rests on science in the service of diplomacy. Its International Monitoring System (IMS), already operating with more than 300 stations and laboratories in over 90 countries, uses seismic, hydroacoustic, infrasound and radionuclide technologies to detect any nuclear explosion. Data from this network flow to the International Data Centre in Vienna, where they are processed around the clock and made available to all signatory States.
This transparency builds confidence. All States rely on the same objective information to assess adherence to the Treaty and to determine whether a nuclear test has taken place. Even countries that have not yet ratified the Treaty host facilities and benefit from the data. That participation reflects the value and credibility that nations place in a system built through global cooperation.
Those benefits extend well beyond peace and security: IMS data contribute to tsunami warning systems, support disaster response and help advance scientific research and understanding that serve us all.
Holding firm in challenging times
Today’s international climate is marked by heightened tensions and evolving geopolitical dynamics. However, the record leaves little room for doubt: testing has come to an almost complete halt, and States continue to support and use the verification system. This reflects a near-universal view that nuclear testing has no place in the twenty-first century.
IDANT reminds us that change happens when people understand why it matters. Communities affected by past tests carry voices that deserve to be heard. Diplomats, scientists, educators and youth advocates help translate remembrance into prevention. Their work strengthens a culture of responsibility that maintains the silence we expect from test sites across the world.
Approaching 30 years and renewing our commitment
As we observe the International Day against Nuclear Tests, we are also approaching another milestone. In 2026, we will mark 30 years since Comprehensive Nuclear Test-Ban Treaty was opened for signature. Anniversaries invite reflection, not only on what has been achieved but also on the work that lies ahead.
Our Treaty has already had a profound impact. Nuclear test explosions have become extremely rare, and the verification regime operates with global reach and trust. We look forward to the day when Treaty enters into force, enabling all elements of the verification regime to be deployed.
Achieving this will require the remaining States to take the final step. They have the opportunity to help complete what was started almost three decades ago. Their decision to ratify the Treaty would reinforce a commitment that has already proved its worth and support a system that benefits every region.
This International Day is a reminder that the absence of nuclear test explosions is not a matter of chance. It is the outcome of decades of dedication and collaboration. Let us continue to uphold that achievement.
In a noisy world, progress can sound like nothing at all. May the measure of our vigilance be silence of in place of nuclear testing, everywhere, for all time.
