By banning all nuclear explosions, the Comprehensive Test Ban Treaty (CTBT) will:

• Constrain the development and qualitative improvement of nuclear weapons;

• End the development of advanced new types of nuclear weapons;

• Contribute to the prevention of nuclear proliferation and the process of nuclear disarmament; and

• Strengthen international peace and security.

The CTBT thus marks an historic milestone in our efforts to reduce the nuclear threat and build a safer world.

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 Treaty shall be open to all states for signature before its entry into force, and any state can accede to the Treaty after that date. Thus, its participation can be universal.

CTBT's Central Features

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

• 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.

• 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.