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
- 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
- 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
- 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.