People at the exhibition

Secretary-General's message 2021

Today marks the 30th anniversary of the closure of Semipalatinsk nuclear test site in Kazakhstan, the largest nuclear test site in the Soviet Union. The closure of that site, where more than 450 nuclear tests took place, signaled the end of the era of unrestrained nuclear testing. Soon afterwards, countries started negotiating the Comprehensive Nuclear-Test-Ban Treaty, the CTBT, which was adopted five years later.

Nuclear tests caused enormous human suffering and environmental damage. They had terrible consequences on the health of people living in affected areas. Many were relocated from their ancestral lands, disrupting their lives and livelihoods. Pristine environments and ecosystems were destroyed, which will take decades, if not centuries, to heal.

In the three decades following the closure of the Semipalatinsk site, we have witnessed the gradual development of a norm against nuclear testing. The CTBT bans all explosive nuclear weapons tests anywhere, by any country, putting a brake on the nuclear arms race and providing a powerful barrier to the development of new nuclear weapons. However, the full potential of the CTBT has not been realized, as the treaty has not entered into force despite its near universal acceptance among States.

I once again urge those states that have not yet ratified the treaty to do so without delay. Eight States whose ratifications are necessary for the Treaty to enter into force have a special responsibility. At the same time, all States should maintain or implement moratoria on nuclear explosions.

The International Day Against Nuclear Tests is an opportunity to reaffirm our commitment to outlaw all nuclear tests, by anyone, anywhere. There is no excuse to delay achieving this goal.