Project for the CTBT

The Arms Control Association's Project for the Comprehensive Test Ban Treaty provides information about the treaty & activities to secure its entry into force.

[Arms Control Assoc @ArmsControlNow]

OTD at 5:30 am near Alamogordo, NM the U.S. conducted the first nuclear weapon test explosion, Trinity. The radioactive fallout reached 46 states, Canada and Mexico w/in 10 days. Downwinders and the global security are still suffering the consequences: https://t.co/zv64ZlZNHY

[Daryl G Kimball @DarylGKimball]

"Nuclear fallout gave her cancer. Now she’s a dogged voice for America’s downwinders" https://t.co/ghXFudNjSP A wonderful profile of the amazing Mary Dickson who has for years lead efforts to help others who have been affected and to halt nuclear weapons testing forever.

[CTBTO @CTBTO]

Preparations for the Integrated Field Exercise 2026 (IFE26) continue at full pace! Following the recent training of surrogate inspectors, 48 experts from 18 countries, who will play various roles other than inspection team members, were in Namibia preparing for #CTBTO's largest-ever IFE. Working across the exercise's supporting teams, each participant has a specific role to play, from managing and coordinating the exercise to supporting scenario, evaluating performance and capturing lessons learned. https://t.co/F0LAjUqoIk

[Arms Control Assoc @ArmsControlNow]

Today is the 80th anniversary of "Able," the first in a series of 67 horrific U.S. nuclear test explosions in the South Pacific. Tests that displaced indigenous islanders and led to decades of harm and human suffering. See: https://t.co/dnsE1YFgQh and https://t.co/3FF9FVuxbF

[CTBTO Youth Group (CYG) @Youth4CTBT]

New Publication Alert 📚

We are excited to announce that the 2025 CTBTO Research Fellowship Collection of Research Papers is now available!

Discover 10 insightful research papers produced by the 5th Cohort of CTBTO Research Fellows here:
https://t.co/H5ZoVxdAQV

Happy reading!

[Daryl G Kimball @DarylGKimball]

"Cracks in the Foundation of the NPT," my take on the #RevCon in Arms Control Today https://t.co/xRnvLC8LYs Repairing the imperfect but irreplaceable NPT regime and achieving real progress on disarmament is not optional. But it will take time, creativity, and smarter leadership.

[Arms Control Assoc @ArmsControlNow]

ACA Press Statement on Results of 11th #NPT Review Conference: https://t.co/JU0PkI1HDi "A missed opportunity to formally reaffirm their support for the treaty and its core principles, goals, and objectives at a time of increasing nuclear dangers."

[Daryl G Kimball @DarylGKimball]

@dohungviet U.S. delegation also likely the only state still pressing to water down Para 8, which minimally reaffirms global support for the CTBT, recalls the need for the N5 to ratify, commends the work of the CTBTO, and warns of the dangers of testing. Such efforts must be rejected. 2/2

[Daryl G Kimball @DarylGKimball]

Issued in the very early hours of May 21 by Conf. President Amb @dohungviet here is Rev. 3 of the draft final outcome document for the 11th #NPTRevCon: https://t.co/EhUg4tCtyc A couple of broad observations upon a first review of the document ... 1/

[Daryl G Kimball @DarylGKimball]

As expected, at least one N5 state is testing the limits of consensus at #NPT2026 on the issue of the CTBT. All other NPT states need to hold firm even if one malign actor demands otherwise. Anything less would be a major retreat from one of the NPT’s core goals and objectives.

[Arms Control Assoc @ArmsControlNow]

"Into the Final Week of #NPT2026: Can the NPT States Come Together on a Final Document?" Analysis and reporting from New York and Washington by @DarylGKimball and Libby Flatoff via the ArmsControlNow blog: https://t.co/20QKHeXbL5

[Daryl G Kimball @DarylGKimball]

@dohungviet Energy Sec. Wright told Congress Wednesday there's no need not resume explosive nuclear testing, though he acknowledged @POTUS could choose to do so for reasons beyond technical necessity. Translation: Trump's threat to resume testing is about retribution not rationality #NPT2026

[Daryl G Kimball @DarylGKimball]

#NPT2026 Review Conference President @dohungviet announces release of revised outcome document, Rev 1. https://t.co/z0DwczBG5L Says it represents our best chance for consensus, urges flexibility, calls for states to bring concrete proposals on how to bridge remaining differences.

[Daryl G Kimball @DarylGKimball]

"Crosswinds Swirl Around 11th NPT RevCon in Week Two," by Libby Flatoff and Daryl Kimball via the Arms Control Now Blog, May 11, 2026 https://t.co/mw6sz4iITI #NPT2026 "Zero draft" elicits support, suggestions, and reveals disagreements that may - or may not - be resolvable.

[Daryl G Kimball @DarylGKimball]

"Head of organization overseeing nuclear test ban treaty issues warning to US and Russia" https://t.co/Q5G9oDta1O via @Newsday #NPT2026

[Arms Control Assoc @ArmsControlNow]

"The 11th NPT RevCon: Choppy Waters Through Week 1; Rough Seas Ahead," a summary of key developments at #NPT2026 by LIbby Flatoff and @DarylGKimball on the Arms Control Now Blog: https://t.co/om7EhFPdOK

[The Cradle @TheCradleMedia]

Nuclear test ban treaty stalled as major powers hold back ratification
——
The head of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) warned on 30 April that mounting geopolitical tensions and stalled ratifications are undermining decades of efforts to curb nuclear testing.

“The geopolitical context is certainly worrying, a lot of uncertainty,” Executive Secretary Robert Floyd said, pointing to growing pressure on arms control agreements and renewed rhetoric around nuclear testing and potential use.

Although the treaty has been signed by 187 states and ratified by 178, it remains unenforced as key powers – including the US, Russia, and China – have yet to ratify it.

Floyd said progress depends on coordinated action among these states, noting it is “quite unlikely” any would move forward alone, adding “I don’t have good news to report … at the moment.”

[Daryl G Kimball @DarylGKimball]

Today SecDef Hegseth testifies before a House committee, and his testimony reiterates Trump's threat to resume nuclear explosive testing "on an equal" basis. Such talk is dangerous and illogical. A few thoughts on why based on my recent column: https://t.co/Let2FVwzkS 1/

[CTBTO @CTBTO]

Day 2 at #NPTRevCon brought clear expressions of support for the #CTBT. An @theELN side event explored ways to strengthen the CTBT to safeguard the NPT, followed by the opening of a French 🇫🇷 exhibition marking 30 years since the CTBT opened for signature.

[European Leadership Network (ELN) @theELN]

📢 TODAY at #NPTRevCon, join @theELN and @NorwayMFA for our joint side event 'Strengthening the CTBT to safeguard the NPT' in CR12 from 13:15.

Who?👉 @DrRobFloyd (@CTBTO), Dr @JanaBaldus (@TheELN), Director Jet Olfato (@DFAPHL), State Secretary @EivindVP (@NorwayMFA) and @DarylGKimball (@ArmsControlNow), moderator @meier_oliver

Why? https://t.co/vpcf8yRsdX