Comprehensive Test Ban Treaty

The Purpose of the Comprehensive Test Ban Treaty

The Comprehensive Test Ban Treaty (CTBT) marks an historic milestone in our efforts to reduce the nuclear threat and build a safer world.

• The CTBT will prohibit any nuclear explosion whether for weapons or peaceful purposes.

• The cessation of all nuclear weapon test explosions and all other nuclear explosions, by constraining the development and qualitative improvement of nuclear weapons, constitutes an effective measure of nuclear disarmament and nonproliferation in all its aspects.

• It will thus contribute effectively to the prevention of nuclear proliferation and the process of nuclear disarmament and enhance international peace and security.

The CTBT Parties

The CTBT was negotiated in the Geneva Conference on Disarmament (CD), recently expanded to include 61 member states, between January 1994 and August 1996. The United Nations General Assembly voted on September 10, 1996 to adopt the Treaty by a vote of 158 in favor, 3 opposed, and 5 abstentions. Since September 24, 1996, the Treaty has been open to all states for signature before its entry into force. 146 nations have now signed. Any other state can accede to the Treaty at any time, enabling its participation to be universal.

CTBT's Central Features

• Basic obligations. The CTBT will ban any nuclear weapon test explosion or any other nuclear explosion, consistent with President Clinton's August 11, 1995 decision to negotiate a true zero yield CTBT.

• Organization. The Treaty establishes an organization to ensure the implementation of its provisions, including those for international verification measures. The organization includes a Conference of States Parties, an Executive Council and a Technical Secretariat, which shall include the International Data Center.

• Structure. The Treaty includes a Protocol in three parts: Part I details the International Monitoring System (IMS); Part II on On-Site Inspections (OSI); and Part III on Confidence Building Measures. There are two Annexes: Annex 1 details the location of treaty monitoring assets associated with the IMS; and Annex 2 details the parameters for screening events.

• Verification and inspections. The Treaty's verification regime includes an international monitoring system composed of seismological, radionuclide, hydroacoustic and infrasound monitoring; consultation and clarification; on-site inspections; and confidence building measures. The use of national technical means, vital for the Treaty's verification regime, is explicitly provided for. Requests for on-site inspections must be approved by at least 30 affirmative votes of members of the Treaty's 51-member Executive Council. The Executive Council must act within 96 hours of receiving a request for an inspection.

• Treaty compliance and sanctions. The Treaty provides for measures to redress a situation and to ensure compliance, including sanctions, and for settlement of disputes. If the Conference or Executive Council determines that a case is of particular gravity, it can bring the issue to the attention of the United Nations.

• Amendments. Any state party to the Treaty may propose an amendment to the Treaty, the Protocol, or the Annexes to the Protocol. Amendments shall be considered by an Amendment Conference and shall be adopted by a positive vote of a majority of the States parties with no State party casting a negative vote.

• Entry into force. The Treaty will enter into force 180 days after the date of deposit of the instruments of ratification by all States listed in Annex 2 to this Treaty, but in no case earlier than two years after its opening for signature. Annex 2 includes 44 States members of the Conference on Disarmament (CD) with nuclear power and/or research reactors. If the Treaty has not entered into force three years after the date of the anniversary of its opening for signature, a conference of the States that have already deposited their instruments of ratification may convene annually to consider and decide by consensus what measures consistent with international law may be undertaken to accelerate the ratification process in order to facilitate the early entry into force of this Treaty.

• Review. Ten years after entry into force, a Conference of the States Parties will be held to review the operation and effectiveness of this Treaty.

• Duration. The Treaty is of unlimited duration. Each State Party has the right to withdraw from the CTBT if it decides that extraordinary events related to its subject matter have jeopardized its supreme national interests.

• Depository. The Secretary General of the United Nations shall be the Depository of this Treaty and shall receive signatures, instruments of ratification and instruments of accession.