Members of CTBTO Group of Eminent Persons warn against any demonstration nuclear test explosion

29 May 2020, Vienna, Austria

Members of the CTBTO Group of Eminent Persons (GEM) issued the following statement in reaction to media reports that senior officials in the United States have discussed the possibility of conducting a demonstration nuclear test explosion:

“We express our deep concern regarding credible press reports that senior U.S. officials have discussed the possibility of conducting a demonstration nuclear test explosion, which would, if carried out, break the global moratorium on nuclear weapon test explosions and severely undermine the Comprehensive Nuclear Test Ban (CTBT) regime, established to help detect and deter nuclear weapon test explosions anywhere in the world.

“Nuclear weapon test explosions, for any purpose, are a vestige of a bygone era. Only one state this century has detonated nuclear weapon tests, and today all of the world’s nuclear armed states are observing nuclear test moratoria. “The most effective way to resolve possible concerns about very low-yield nuclear explosions and enforce compliance with the 1996 Comprehensive Nuclear-Test-Ban Treaty, is to bring the treaty into force. This requires ratification by eight remaining hold-out states, including the United States, China, DPRK, Egypt, India, Iran, Israel, and Pakistan. When it does enter into force, states have the option to demand intrusive, short-notice on-site inspections to investigate suspicious activities. “We urge all responsible states to reiterate their strong support for the global norm against nuclear test explosions of any yield that has been established by the CTBT, to take concrete action to secure its prompt entry into force, and to urge the use of diplomacy rather than intimidation to build a more peaceful and secure international security environment for all.”

Nobuyasu Abe
Hans Blix
Grigory Berdennikov
Desmond Browne
Jayantha Dhanapala
Sérgio de Queiroz Duarte
Thomas Hajnoczi
President Tarja Halonen
Wolfgang Hoffmann
Angela Kane
Kim Won-soo
Ho-Jin Lee
Patricia Lewis
Kevin Rudd
Ahmet Üzümcü


The Group of Eminent Persons (GEM) supports and complements efforts to promote the Treaty’s entry into force, as well as reinvigorating international endeavours to achieve this goal. The CTBT bans all nuclear explosions, thus hampering both the initial development of nuclear weapons as well as significant enhancements. The Treaty also helps prevent harmful radioactive releases from nuclear testing.

The CTBT has so far been signed by 184 States, of which 168 have ratified the Treaty. However, its demanding entry-into-force provision requires 44 particular “nuclear technology holder” States to ratify the Treaty for it to enter into force. Eight of them have yet to ratify: China, the Democratic People's Republic of Korea (DPRK), Egypt, India, Iran, Israel, Pakistan, and the United States. (China, Egypt, Iran, Israel, and the United States have already signed the Treaty.)

A verification regime to monitor the globe for nuclear explosions is nearing completion with currently more than 300 facilities certified out of the 337 originally planned for International Monitoring System (IMS) facilities already in operation. The system has proved its capabilities to detect even small nuclear tests during the announced DPRK nuclear tests in 2006, 2009, 2013, 2016 and 2017.