Revisiting the Comprehensive Test Ban Treaty: An Agenda Item for the Next Administration


2012-09-24 By Richard Weitz

A major subject of discussion at the 2012 Moscow Nonproliferation Conference was the Comprehensive Test Ban Treaty (CTBT).

Whether to ratify the treaty will also be an issue for the next U.S. presidential administration.

The CTBT prohibits all nuclear explosions, whether for military or other purposes, in any environment. Its practical effect would be to extend the limited testing prohibitions contained in current treaties and agreements to encompass the testing of all nuclear explosive devices underground, the last medium not formally prohibited by the existing bans.

In principle, the CTBT would be superseded by the Nuclear Non-Proliferation Treaty (NPT), which formally commits all State Parties to the goal of universal nuclear disarmament. In practice, achieving a ban on all nuclear weapons testing appears easier to accomplish in the near term than eliminating all nuclear weapons.

As of today, 183 national governments (out of 196 possible signatories) have signed the CTBT and 157 countries have deposited their instruments of ratification with the UN secretary-general. These totals mean that the CTBT enjoys a larger potential membership than most international arms control agreements.

Three countries have not signed the CTBT: Pakistan, India and North Korea. And several have signed but not ratified, including the PRC, the  United States, Israel, Iran and Egypt. Credit Photo: Bigstock

The treaty specifies, however, that it will only enter into force 180 days after all 44 “nuclear-capable states” listed in Annex 2 (those countries that participated in the 1996 Conference on Disarmament session that drafted the treaty text and possessed nuclear research or power reactors at the time the CTBT was opened for signature) have ratified the treaty.

Three Annex 2 states have not signed the CTBT: India, North Korea, and Pakistan. Five Annex 2 countries have signed but not ratified the treaty: the People’s Republic of China, Egypt, Iran, Israel, and the United States.

Five of these so-called “hold-out” states conducted nuclear explosions before the CTBT opened for signature, while several other non-parties are suspected of having or seeking nuclear weapons. Despite their status, only North Korea has not adopted a formal or de facto moratorium on nuclear weapons testing.

Article I of the CTBT bans State Parties from conducting nuclear explosions or encouraging other entities to do so. It does not forbid nuclear-weapons-related research such as “sub-critical experiments” that do not involve self-sustaining nuclear fission chain reactions. The United States, the United Kingdom, the Russian Federation, and other countries conduct these experiments to determine if fission material such as plutonium decays with time in ways that could affect the weapons’ performance.

Article II creates a Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) in Vienna to manage CTBT implementation. It consists of three main organs. The Conference on State Parties holds annual and special meetings of all member states and serves as an authoritative forum for deciding treaty-related issues. The 51-member Executive Council can call special sessions of the Conference, direct CTBT activities in-between Conference sessions, and decide on requests for on-site inspections.

The Technical Secretariat operates the International Monitoring System (IMS), which is a global network of monitoring stations linked to an International Data Center (IDC) in Vienna. The secretariat also conducts on-site inspections and administers the various consultation, clarification, and confidence-building measures detailed in Article IV and the CTBT Protocol designed to verify the treaty’s implementation.

Article III specifies the obligations State Parties undertake to implement the treaty both domestically and with regard to the other CTBT treaty members and the CTBTO. The fifth and sixth articles specify procedures to redress treaty violations and resolve disputed interpretations of the Treaty. The seventh and eighth articles describe how members can amend and review the CTBT. Article IX stipulates that the treaty is of unlimited duration, but that any State Party can withdraw on six months’ notice if it decides that “extraordinary events related to the subject matter of the treaty have jeopardized its supreme interests.”

The drive to end nuclear testing began soon after the advent of nuclear weapons.

During the 1950s, the international disarmament community had redirected its efforts from seeking the rapid elimination of all existing nuclear arsenals to attempting to limit their possible use through various arms control initiatives.

Interest in constraining nuclear testing increased after scientists began publicizing the detrimental effects of radioactive fallout on human health generated by the frequent testing of ever-larger hydrogen bombs. The UK-based Campaign for Nuclear Disarmament, the multinational Pugwash movement, and other groups mobilized mass popular pressures on Western governments to curb nuclear weapons testing.

Verification and other difficulties prevented the three major nuclear weapons states of the time—the United States, the Soviet Union, and the United Kingdom—from accepting a comprehensive prohibition on nuclear testing. The shock of the 1962 Cuban Missile Crisis, which could have easily escalated into a nuclear war, helped induce these three governments into negotiating a compromise agreement the following year.

On October 10, 1963, they adopted a Partial Test Ban Treaty (also known as the Limited Test Ban Treaty), which prohibits nuclear tests in the atmosphere, underwater, and in outer space. Although the cessation of above-ground Soviet and American nuclear detonations decreased public concerns about the adverse heath effects of nuclear testing, various national governments subsequently negotiated additional prohibitions on nuclear testing.

These accords—such as the 1974 Threshold Test Ban Treaty, the 1976 Peaceful Nuclear Explosions Treaty, and the treaties proscribing nuclear testing in Outer Space or on Antarctica—constrain the size and location of nuclear detonations. The treaties establishing regional nuclear-free-zones have also prohibited nuclear weapons testing in certain geographic areas.

After the end of the Cold War, the governments of Europe, Russia, and the United States renewed their efforts at extending the existing hodgepodge of limited nuclear test ban accords—which still permitted low-yield underground nuclear testing—into a Comprehensive Test Ban Treaty. Not only had the means of verification needed to underpin a complete ban on nuclear testing improved since the 1970s, but the five “nuclear weapons states” recognized under the NPT (China, France, Russia, the United Kingdom, and the United States) separately adopted unofficial unilateral moratoria on further nuclear testing during the 1990s.

The delegates to the Geneva-based Conference on Disarmament (CD), an autonomous affiliate of the UN that operates by consensus, organized extensive talks aimed at adopting a comprehensive test ban from January 1994 and August 1996. After the negotiations failed to achieve unanimous agreement on the treaty’s provisions, the government of Australia submitted the text as a draft resolution rather than a CD document to the UN General Assembly. An overwhelming majority (158 to 3 with 5 abstentions) of the General Assembly members subsequently voted to adopt the text and offer it for signature and ratification.

The CTBT experienced great success in rapidly securing the endorsement of potential member countries.

When the CTBT opened for signature on September 24, 1996, 71 national governments immediately signed the treaty, including all five NPT-recognized nuclear weapons states.

On November 19, 1996, the treaty signatories established a Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO PrepCom) in Vienna to provide institutional support for the treaty. The PrepCom consists of a plenary body comprised of all states whose governments have signed the CTBT and a Provisional Technical Secretariat that has begun constructing the extensive verification infrastructure provided for by the treaty.

Biennial Article XIV Conferences on Facilitating the Entry into Force of the CTBT have convened every other fall, beginning in October 1999, under UN sponsorship. In 2003, the participating states created the position of CTBTO Special Representative to accelerate signing and ratification by the remaining hold-out states.

Britain and France became the first NPT-recognized nuclear weapons states to ratify the CTBT, depositing their instruments of ratification on April 6, 1998. The previous month, the United Kingdom had adopted the Nuclear Explosions (Prohibition and Inspections) Act, which established the legal framework for meeting British obligation under the treaty. In 2007, the British Secretary of State for Defence told the Conference on Disarmament again urged all countries, especially the Article II states, to ratify the CTBT. The Seismology Group at Aldermaston, part of the UK Atomic Weapons Establishment, helped develop the technical means for assessing suspect nuclear explosions.

Of the NPT-designated nuclear weapons states, the United Kingdom would experience the greatest problem in resuming nuclear weapons testing since the country lacks its own nuclear test site and has relied on the Nevada Test Site for decades until Britain ceased testing nuclear weapons in 1991.

At present, the United Kingdom conducts only a few joint sub-critical nuclear experiments with the United States at the Nevada site. Even so, some NGOs, such as Greenpeace UK, claim that the government’s policy of retaining nuclear weapons and acquiring a new nuclear delivery platform in the form of Trident SSBNs threatens to undermine both the CTBT and the NPT.

The French government followed a more contentious path towards the CTBT. When French President Jacques Chirac declared that France would conduct eight nuclear tests at Mururoa Atoll in the South Pacific, his announcement evoked a storm of criticism. Chirac quickly pledged that this would be France’s last test series and that henceforth the French government would support a comprehensive ban on nuclear testing. The last French test occurred in January 1996.

All the other EU members—many of which are Annex II states whose ratification is necessary for the CTBT to enter into force—have presently signed and ratified the treaty.

The government of Japan has also been a strong supporter of the CTBT as well as of other nuclear disarmament measures. In addition to signing and ratifying the treaty themselves, Japanese officials have regularly urged other governments to do so in bilateral as well as multilateral fora. Japanese representatives played a major role in each of the five CTBT entry-into-force conferences.

Moreover, Japan, Australia and Netherlands held a “Friend of the CTBT” Foreign Meeting for the purpose of maintaining and strengthening momentum toward the treaty’s entry into force.  Japan and Australia subsequently jointly launched an International Commission for Nuclear Non-proliferation and Disarmament, which sought CTBT ratification and other arms control measures.

More than many governments, representatives of Japan, an island nation vulnerable to ocean storms and earthquakes, have promoted the use of the IMS to support other Tsunami warning systems. 

Perhaps for this reason, the Japanese government has financed a large-scale program to construct a domestic verification regime—hiring trained personnel and building a network of national verification facilities—that can help anticipate disasters even if the CTBT never enters into force.