30 year ago, the world made a choice: To end nuclear testing. The CTBT was born of that commitment. A turning point. A powerful step forward.
Today that vision is nearly universal. 187 signatures. 178 ratifications. A strong and growing norm - one that holds. At the heart of the Treaty: a verification regime like no other. Over 300 facilities. A global network that leaves no test unseen.
In a time of global uncertainty, the CTBT remains a beacon.
Proof that multilateralism works. That progress is possible. As we mark 30 years of the CTBT, we look ahead.
One Treaty. One Goal. Zero Tests.
Ending Nuclear Tests
The CTBT has created a firm global norm against nuclear testing, with less than a dozen tests conducted since it opened for signature in 1996, compared with more than 2,000 over the five previous decades.
The Treaty
The Treaty was opened for signature in 1996 to stop the development of new nuclear weapons and prevent upgrades to existing ones, supporting global efforts in non-proliferation and disarmament.
Verification Regime
To monitor compliance, its unique verification regime is designed to detect any nuclear explosion conducted anywhere – underground, under water or in the atmosphere.
Resources
CTBT marks 30 years as States gather at NPT Review Conference
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) held a side event on 27 April 2026 on the margins of the 11th Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) at United Nations Headquarters.
CTBTO Executive Secretary Robert Floyd speaking at event