Comprehensive Test Ban Treaty (CTBT)

The Comprehensive Test Ban Treaty (CTBT) prohibits “any nuclear weapon test explosion or any other nuclear explosion” anywhere in the world.

• The treaty was opened for signature in September 1996, and has been signed by 185 nations and ratified by 170.
• The treaty cannot enter into force until it is ratified by 44 specific nations, eight of which have yet to do so: China, India, Pakistan, North Korea, Israel, Iran, Egypt, and the United States.

Monitoring

• In order to verify compliance with its provisions, the treaty establishes a global network of monitoring facilities and allows for on-site inspections of suspicious events.
• The overall accord contains a preamble, 17 treaty articles, two treaty annexes, and a protocol with two annexes detailing verification procedures.

Preamble and Important Articles

• The preamble, which lists disarmament principles and objectives, sets the overall political context of the treaty. In particular, it stresses the need for the continued reduction of nuclear weapons worldwide with the ultimate goal of their elimination.
• Article I establishes that all states parties are prohibited from conducting “any nuclear weapon test explosion or any other nuclear explosion.
• Article II establishes the Comprehensive Nuclear-Test Ban Treaty Organization (CTBTO), which ensures treaty implementation and provides states-parties with a forum for consultation and cooperation. The organization consists of a Conference of the States Parties, an Executive Council and a Technical Secretariat. The organization, which is located in Vienna, is structurally independent from, but operating in collaboration with, the International Atomic Energy Agency (IAEA). The Conference of the States Parties is the overall governing body of the organization. The Executive Council, which meets regularly and acts as the treaty’s principal decision-making body, consists of 51 members.
• Article III requires each state-party, in accordance with its constitutional process, to take any necessary measures to implement its treaty obligations.
• Article IV and the verification protocol establish the treaty’s verification regime, which consists of four basic elements: the IMS, consultation and clarification, on-site inspections, and confidence-building measures. 
• Article VII each state-party has the right to propose amendments to the treaty after its entry into force. Any proposed amendment requires the approval of a simple majority of states-parties at an amendment conference with no party casting a negative vote.
• Article VIII, a conference will be held 10 years after the treaty’s entry into force to review the implementation of its provisions, including the preamble. At this review conference, any state-party may request that the issue of so-called “peaceful nuclear explosions” (PNEs) be put on the agenda.
• Article IX, the treaty has an unlimited duration. In addition, each state-party has the right to withdraw from the treaty if it decides, “extraordinary events related to the subject matter of this Treaty have jeopardized its supreme interests.” Notice of intent to withdraw must be given at least six months in advance.
• Article X specifies that the treaty’s annexes, protocol and annexes to the protocol are a formal part of the treaty.
• Article XI declares that the treaty is open to all states for signature prior to its entry into force.
• Article XII maintains that each signatory state will ratify the treaty according to its own constitutional procedures.
•  Article XIII, any state that has not signed the treaty prior to its entry into force may accede to it any time thereafter.
• Article XIV, the treaty will not enter into force until it has been signed and ratified by 44 states listed by name in Annex 2.
• These states include the five original nuclear weapon states—United States, Russia, Britain, France and China—as well as India, Israel, North Korea, and Pakistan.
• The 44 states, all of which are participating members of the recently expanded Conference on Disarmament, possess nuclear power and research reactors as determined by the IAEA.
• Article XV stipulates that the treaty’s provisions will not be subject to reservations.
• Article XVI establishes the UN Secretary General as the depositary of the treaty.
• Article XVII, the treaty will be authentic in six languages.