The Status of the Comprehensive Test Ban Treaty: Signatories and Ratifiers

Contact: Daryl Kimball, Executive Director, (202) 463-8270 x107

Despite nearly 20 years of global efforts to promote the entry into force of the Comprehensive Test Ban Treaty (CTBT), the treaty’s enactment appears a long way off.

President George H. W. Bush signed into law the unilateral declaration to forego full-scale nuclear weapons testing on October 2, 1992. The United States signed the CTBT on September 24, 1996, the day it opened for signature, but the Senate dealt a severe blow to the near-term prospects for U.S. participation when it refused to provide its advice and consent. On October 13, 1999. President Obama stated in February 2009 that he intended to pursue Senate advice and consent to ratification of the treaty "immediately and aggressively," but he ultimately did not do so.

The CTBT will formally enter into force after 44 designated “nuclear-capable states” (as listed in Annex 2 of the treaty) have deposited their instruments of ratification with the UN secretary-general. To date, 186 states have signed and 174 have ratified the treaty. Of the 44 specified countries, India, Pakistan, and North Korea still have not signed, and only 36 have ratified the treaty.

For more information on the CTBT, see Comprehensive Test Ban Treaty at a Glance.

The following chart identifies the treaty’s signatories and ratifiers. States whose ratification is required for the treaty to take effect are shaded and marked with an asterisk (*).

Total Signatories: 186
Total Ratifiers: 174

Annex 2 Ratifications (out of 44): 36