Login/Logout

*
*  
"...the Arms Control Association [does] so much to keep the focus on the issues so important to everyone here, to hold our leaders accountable to inspire creative thinking and to press for change. So we are grateful for your leadership and for the unyielding dedication to global nuclear security."
– Lord Des Browne
Vice Chairman, Nuclear Threat Initiative
Project for the CTBT


The Project for the CTBT supports the work of NGOs and experts to build public and policymaker understanding of the Comprehensive Test Ban Treaty. Launched in 2008 at time of renewed interest in the United States on the treaty, the project’s purpose is to provide information on the history and issues surrounding the treaty and reports on key developments relating to nuclear testing, progress toward entry into force of the CTBT, and the work of the CTBT Organization (CTBTO).

Contact: Daryl G. Kimball, 202-463-8270 ext. 107 or Shannon Bugos, 202-463-8270 ext. 113


The Case for the Comprehensive Nuclear Test Ban Treaty

For the first five decades of the nuclear age, nuclear weapon test explosions were the most visible symbol of the dangers of nuclear weapons, nuclear arms racing, and the omnipresent danger of nuclear war—or as President John F. Kennedy described it, the nuclear “Sword of Damocles” that hangs over every man, women and child on the planet.

Following the end of the Cold War, Russia, after conducing 715 nuclear tests, in 1991 and the United States, after 1,030 nuclear tests, in 1992 halted nuclear testing. National and international pressure to maintain the moratorium was strong, and talks on a comprehensive test ban treaty began in 1994.

In September 1996, the United States became the first nation to sign the Comprehensive Nuclear Test Ban Treaty (CTBT), which “prohibits any nuclear weapon test explosion or any other nuclear explosion” and establishes a global monitoring network and the option of short-notice, on-site inspections that improves capabilities to detect and deter cheating.

Today, there is no military requirement for new nuclear weapons capabilities that might require the resumption of nuclear testing by the United States or other nuclear-armed states. The U.S. nuclear weapons laboratories do not need nuclear explosive testing to maintain the effectiveness of the existing U.S. nuclear arsenal.

The CTBT brought the era of frequent nuclear testing to an end and established a strong norm against any kind of nuclear test explosion. The treaty has near-universal support with 184 signatories, including the five original nuclear testing states: China, France, Russia, the United Kingdom, and the United States.

The Comprehensive Test Ban Treaty Organization (CTBTO), with headquarters in Vienna, is operating on a 24/7 basis to collect and analyze data in real time from a global network of nuclear test monitoring stations. The CTBTO’s International Monitoring System, which is nearly complete and is operating on a 24/7 basis, serves as a strong deterrent against any state that might consider conducting a clandestine nuclear test explosion.

However, the door to nuclear testing remains open as the treaty has not entered into force due to the treaty’s onerous Article XIV provisions, which require that 44 specific states sign and ratify. Currently there are eight “hold out” states—China, the Democratic People’s Republic of Korea (DPRK), Egypt, India, Iran, Israel, Pakistan, and the United States—which have failed to ratify.

The non-testing norm cannot be taken for granted and, over time, it must be actively renewed and reinforced. In order to realize the full potential of the treaty, close the door on further nuclear testing, and reinforce the nonproliferation regime, states must rejuvenate their efforts to achieve the entry into force of the CTBT.

Unfortunately, the United States, which was leading proponent for the CTBT during the 1990s, is now lagging behind. Without explanation or a high-level review or consultation with allies, the Donald Trump administration announced in February 2018 that it would not seek Senate approval for U.S. ratification of the CTBT.

It is in the interest of U.S. national security to curb the spread of nuclear weapons, prevent nuclear weapons testing by others, and improve U.S. and international capabilities to detect, deter, and respond to possible cheating. Even though the United States has already assumed most CTBT-related responsibilities, it cannot reap the full security benefits of the CTBT until the Senate approves the treaty by a two-thirds majority.

Bipartisan leaders and security experts agree that by ratifying the CTBT, the United States stands to gain an important constraint on the ability of other states to build new and more deadly nuclear weapons that could pose a threat to U.S. security.

CTBT’s Increasing National Security Value

Global efforts to stop the spread of nuclear weapons are in jeopardy. The international legal framework built to stop the spread and use of nuclear weapons, held together by the nuclear Nonproliferation Treaty (NPT), is under stress. Now, unpredictable nations such as North Korea  have active nuclear programs, and nonproliferation agreements like the Joint Comprehensive Plan of Action (JCPOA) with Iran hang by a thread.

U.S. ratification of the CTBT is an essential first step to rebuilding international support for measures to prevent the use and spread of nuclear weapons. In 1995, the United States and the other nuclear powers promised to deliver on the CTBT in exchange for the indefinite extension of the NPT. Long overdue action on the CTBT now would give the United States more leverage to win support for tougher nuclear safeguards and more effective responses to cases of noncompliance.

A global verifiable ban on testing would constrain the ability of nuclear-armed states, such as China, to develop new and more deadly nuclear weapons. Without nuclear weapon test explosions, would-be nuclear-armed nations or emerging nuclear-armed nations, like North Korea, would not be able to proof test the more advanced, smaller nuclear warhead designs that could be used to arm ballistic missiles.

Proven Ability to Maintain the Arsenal

Over the past decade, the success of the Stockpile Stewardship Program has demonstrated that the effectiveness of the U.S. nuclear arsenal can be maintained under a CTBT. Life Extension Programs (LEPs) have refurbished and recertified major warhead types without nuclear testing. Key plutonium parts in warheads have been shown to last at least 85 years or even more than 100 years, much longer than previously thought in either case, and limited production capacity has been established to remanufacture new parts when needed, making new-design "replacement" warheads unnecessary.

The United States has no need to resume nuclear testing. It already has the most advanced and deadly nuclear arsenal in the world. The United States has conducted 1,030 nuclear tests, more than all other nations combined, including Russia (715) and China (45). Given this advantage, it is clearly in U.S. national security interests to prevent other nations from testing nuclear weapons.

Proven Ability to Verify Compliance

Today, no would-be cheater of the CTBT could confidently conduct an undetected nuclear explosion large enough to threaten U.S. security. The international verification system, together with U.S. national technical means of verification, will detect militarily significant tests. However, unless it ratifies the treaty, the United States cannot take advantage of the international system’s full benefits, such as on-site inspections.

Currently, more than 90 percent of the CTBT’s 337 monitoring stations have been built. North Korea’s nuclear test explosions in 2006 and 2009 demonstrated that the CTBT verification system is working well and can detect very small explosions with high confidence. The August 2018 explosion on Russia’s White Sea coast, which potentially involved a nuclear-powered cruise missile, also demonstrated the importance of the CTBT verification and monitoring regime.

The Importance of U.S. Leadership

The CTBT has now been signed by 184 nations, including China, France, Russia, the United Kingdom, and the United States, and ratified by 168, including Australia, Japan, Russia, South Korea, and all of the United States’ NATO allies. The CTBT’s entry into force awaits ratification by eight states: China, Egypt, India, Iran, Israel, North Korea, Pakistan, and the United States.

U.S. ratification would spur other key nations, such as China, India, and Pakistan, to ratify the treaty and would reinforce the global taboo against nuclear testing. Without positive U.S. action on the CTBT, the risks of nuclear weapons proliferation and the resumption of testing will only grow.

The Time for the CTBT is Now

U.S. approval of the CTBT would reinforce the global test moratorium and accelerate the treaty’s formal entry into force, helping to constrain the ability of other nuclear-armed states to improve their nuclear bombs.

Equally important, U.S. ratification of the CTBT would reestablish strong U.S. leadership in stopping the spread of nuclear weapons to additional nations and to terrorist groups. The CTBT would strengthen U.S. and international security for years to come.


History of Efforts for the CTBT

For decades, nuclear testing has been used to develop new nuclear warhead designs and demonstrate nuclear weapons capabilities by the world’s nuclear-armed states. A global halt to nuclear weapons testing was first proposed in 1954 by Indian Prime Minister Jawaharlal Nehru as step toward ending the nuclear arms race and preventing proliferation.

A global halt to nuclear testing has been a central, bipartisan national security objective of the United States since the late 1950s, when President Dwight Eisenhower sought a comprehensive test ban. The United States and Russia halted nuclear testing from 1958 to 1960 but failed to conclude a permanent ban.

From 1962-63, President John F. Kennedy pursued comprehensive test ban talks with Russia, but the two sides could not agree on the number of on-site inspections, and the two sides instead agreed to the Limited Test Ban Treaty (LTBT), which prohibits nuclear test explosions in the atmosphere, in outer space, and underwater.

President Jimmy Carter again sought to negotiate a comprehensive test ban treaty with Russia from 1977-1980, but that effort also fell short as U.S.-Soviet relations soured after Moscow's invasion of Afghanistan.

In 1992, following the end of the Cold War and a Russian nuclear test moratorium declared the previous year, President George H.W. Bush announced a halt to the development of new types of nuclear warheads. That same year, Congress mandated a 9-month moratorium on nuclear weapon test explosions. In July 1993, President Bill Clinton extended the U.S. test moratorium.

In 1994, the world's nations finally came together to negotiate the Comprehensive Nuclear Test Ban Treaty (CTBT) to help curb the spread of nuclear weapons and ensure an end to the nuclear arms competition.

In September 1996, the United States was the first nation to sign the CTBT, which prohibits all nuclear weapon test explosions or other nuclear explosions. The CTBT also establishes a global monitoring network called the International Monitoring System (IMS) and provides for the option of short-notice on-site inspections to detect and deter cheating. The Preparatory Commission for the Comprehensive Test Ban Treaty Organization (CTBTO) was founded in order to promote the treaty, establish the verification regime, and help bring about the treaty’s entry into force.

The U.S. Senate declined to give its advice and consent to ratification when it briefly considered the CTBT in October 1999. Many senators who voted "no" expressed concerns about the technical challenges of verification and the ability of the United States to maintain its arsenal without testing. Since then, significant advances in test ban monitoring and the nuclear weapons stockpile stewardship program have addressed many of the concerns expressed during the first Senate debate.

In recent years, international support for the CTBT has grown. An increasing array of Republican and Democratic national security leaders including former Secretaries of State George Shultz and Henry Kissinger, former Secretary of Defense William Perry, and former National Security Advisor General Brent Scowcroft have all endorsed U.S. ratification of the CTBT.

On April 5, 2009, President Barack Obama said: "To achieve a global ban on nuclear testing, my administration will immediately and aggressively pursue U.S. ratification of the Comprehensive Test Ban Treaty. After more than five decades of talks, it is time for the testing of nuclear weapons to finally be banned."

There is neither the need nor the political support for renewed U.S. nuclear weapons testing, and it is in the national security interest of the United States to ratify the CTBT to prevent nuclear weapons testing by others.


The National and International Security Value of the CTBT

With or without the CTBT, it is highly unlikely that the United States will ever conduct another nuclear explosive test. There is no technical or military requirement to resume U.S. testing, nor the political will to do so.

On Nov. 28, 2011, Linton Brooks reiterated a statement, saying "as a practical matter, it is almost certain that the United States will not test again. The political bar against testing is extremely high. I have been in and out of government for a long time. And in recent years, I never met anybody who advocated that we seek authorization to return to testing." Brooks served as the administrator of the National Nuclear Security Administration under President George W. Bush from 2002-2007.

At the same time, it is in the U.S. interest to ensure that other nations do not resume nuclear testing, which could help them perfect new and more advanced types of nuclear weapons. Even though the United States has already assumed most CTBT-related responsibilities, it cannot reap the full security benefits of the CTBT until the Senate approves the treaty by a two-thirds majority.

The CTBT helps block new nuclear threats from emerging, thereby strengthening U.S. and global security. By banning all nuclear weapon test explosions, the CTBT makes it harder for nations that already possess nuclear weapons to perfect newer and more sophisticated nuclear weapons. For instance, a new round of Chinese nuclear weapon test explosions would enable China to miniaturize its warhead designs and allow China to place multiple warheads on its relatively small arsenal of strategic ballistic missiles. This would give China the ability to rapidly increase its long-range nuclear strike force, which is currently less than 40 weapons.

Without nuclear weapon test explosions, would-be nuclear-armed nations or emerging nuclear-armed nations, like North Korea, would not be able to develop and proof test the more advanced, smaller nuclear warhead designs that could fit on ballistic missiles.

As Dr. Siegfried Hecker, former director of Los Alamos National Laboratory, said in October 2009: “The single most important reason to ratify the CTBT is to stop other countries from improving their arsenals.”

Ratification of the CTBT would restore U.S. leadership on nonproliferation and bolster efforts to curb the spread of nuclear weapons to additional states or terrorists. In 1995, the United States and the other nuclear powers promised to deliver on the CTBT in exchange for the indefinite extension of the nuclear Nonproliferation Treaty. U.S. ratification of the CTBT is critical to achieving agreement on new measures to strengthen global nonproliferation rules, such as more effective international nuclear safeguards, tougher penalties against states that violate their commitments, and accelerated efforts to secure vulnerable nuclear material.

As Secretary of State Hillary Clinton said on Oct. 21, 2009, “Bringing the [CTBT] into force will strengthen and reenergize the global nonproliferation regime and, in doing so, enhance our own security.”

The current arms control architecture is in a perilous state. The United States withdrew from the Joint Comprehensive Plan of Action in May 2018 and the Intermediate-Range Nuclear Forces Treaty, which banned an entire class of nuclear delivery systems, in August 2019, and has started to deploy a new nuclear warhead at the end of 2019. By ratifying the CTBT, the United States can start to reaffirm its commitment to nonproliferation and assure the world that it will not restart nuclear weapons testing, and it would help move China to ratify the treaty.

Ratification of the CTBT would improve U.S. capabilities to detect, deter, and respond to potential cheating. The United States’ capability to detect and deter possible clandestine nuclear testing by other states will be significantly greater with the CTBT in force than without it. U.S. ratification of the CTBT is essential to making short-notice, on-site inspections possible and maintaining long-term political and financial support from other nations for the operation of the CTBTO’s International Monitoring System and International Data Center.

There is nothing to gain and much to lose by delaying action on the CTBT. While it might be possible to sustain the unilateral moratoria undertaken by the nuclear testing states for several years, uncertainties and the risk of a resumption of testing will only grow over time. Without the CTBT in force, concerns about clandestine nuclear testing might arise that could not be resolved in the absence of inspections provided for under the treaty. Failure to achieve U.S. ratification of the CTBT would increase uncertainty and reduce U.S. security.


Stockpile Stewardship Under the CTBT

The United States has not conducted a nuclear test since 1992—a bipartisan policy maintained through five successive administrations. Since then, it has become clear that maintaining the reliability of proven U.S. nuclear warhead designs does not depend on nuclear test explosions.

The U.S. arsenal has been and will continue to be maintained without nuclear testing indefinitely through non-nuclear tests and evaluations, combined with the refurbishment of key components to previous design specifications. Since 1994, each warhead type in the U.S. nuclear weapons arsenal has been determined to be safe and reliable through a rigorous certification process instituted following the end of U.S. nuclear testing.

According to a 2002 National Academies of Science (NAS) panel report that included three former nuclear weapons lab directors, age-related defects mainly related to non-nuclear components can be expected, "but nuclear testing is not needed to discover these problems and is not likely to be needed to address them."

For more than fifteen years, a nationwide infrastructure of nuclear weapons research, evaluation, and manufacturing sites and laboratories has been maintained through the Stockpile Stewardship Program (SSP). Currently, the United States spends $5-7 billion annually on its Stockpile Stewardship Program, which includes nuclear weapons surveillance and maintenance, non-nuclear and subcritical nuclear experiments, sophisticated supercomputer modeling, and life-extension programs for the existing warhead types in the enduring U.S. nuclear stockpile.

Confidence in the ability to maintain U.S. warheads is increasing—not decreasing. A 2002 National Academy of Science (NAS) panel report found that the current Stockpile Stewardship Program provides the technical capabilities that are necessary to maintain confidence in the safety and reliability of the existing nuclear stockpile, "provided that adequate resources are made available...and are properly focused on this task." The report was updated in 2012 and reinforced the same conclusion.

The United States is currently modernizing its nuclear triad, a process that began under the Obama administration and will potentially cost as much as $1.7 trillion over the course of 30 years. This U.S. modernization plan should give senators greater confidence that there is a long-term strategy and more than enough funding to continue to maintain the U.S. arsenal effectively.

In 2011, NNSA Administrator Thomas D’Agostino told Arms Control Today, “[I]n my opinion, we have a safe and secure and reliable stockpile. There’s no need to conduct underground [nuclear] testing.”

As for plutonium pits, the Department of Energy announced in 2006 that studies by Lawrence Livermore and Los Alamos National Laboratories concluded that “the minimum lifetime for plutonium pits was at least 85 years—25 to 40 years longer than previously estimated.” A 2007 study by JASON stated that plutonium pits “have credible minimum lifetimes in excess of 100 years.”

In a September 2009 report, the JASON independent technical review panel concluded that "lifetimes of today's nuclear warheads could be extended for decades, with no anticipated loss in confidence." These findings indicate that new-design replacement warheads are not needed to maintain reliability.

Senate approval of the CTBT would further help to strengthen bipartisan support for effective stockpile stewardship efforts to ensure that as long as nuclear weapons exist, the U.S. nuclear arsenal remains effective without nuclear testing and without the production of newly-designed warheads. In the exceedingly unlikely event that the president of the United States decides to resume nuclear testing, the United States has the option of exercising the CTBT’s “supreme national interest” withdrawal clause.


Verification of the CTBT

Detecting a nuclear weapon test explosion has become so effective that no would-be cheater could be confident that a nuclear explosion that would adversely affect U.S. security would escape detection, thereby providing a reliable deterrent against cheating.

Verification capabilities will be even greater with the CTBT in force, which would include its global verification and monitoring network, as well as the option of short-notice on-site inspections (OSI), performed by the CTBTO. Through these mechanisms, the CTBT gives the U.S. tools otherwise unavailable to resolve compliance concerns and respond effectively to potential nuclear testing by other states.

The CTBT establishes a far-reaching International Monitoring System (IMS) to detect potential nuclear explosions using four technologies: seismic, hydroacoustic, radionuclide, and infrasound, including a new array of highly-capable “noble gas” monitoring stations that can detect minute amounts of the radioactive gases emitted by underground explosions into the atmosphere. More than 90 percent of the CTBT’s 337 monitoring stations have been built.

The CTBT provides for monitoring stations inside Russia, China, and other sensitive locations, including some places where the United States could not gain access on its own. (Click here to explore the CTBTO’s interactive map of IMS stations.)

The International Data Center (IDC) based in Vienna collects and analyzes information from the IMS and disseminates the raw and processed data to member states for their own evaluation.

The treaty also allows the United States and other member states to monitor CTBT compliance by using their own, highly-sophisticated satellites and other national technical means. Tens of thousands of high-quality civilian seismic stations around the world provide further detection capabilities.

Today, nuclear test explosion monitoring capabilities are excellent and getting better. During the Senate debate on the CTBT in 1999, some critics claimed that the IMS could only monitor for underground explosions at yields at or above one kiloton TNT equivalent. In reality, actual nuclear test explosion monitoring capabilities were much better and have only improved since then.

A 2002 National Academy of Sciences (NAS) panel report determined that “underground nuclear explosions can be reliably detected and can be identified as explosions, using IMS data down to a yield of 0.1 kilotons (100 tons) in hard rock if conducted anywhere in Europe, Asia, North Africa, and North America.”

Advances in regional seismology have provided additional confidence. For some locations (such as Russia’s former nuclear test site at Novaya Zemlya), the use of new seismic arrays and regionally located seismic stations has lowered the detection threshold to below 0.01 kilotons (10 tons).

North Korea’s nuclear tests in 2006 and 2009 demonstrated that the CTBT verification system is working well and can detect very small explosions. When North Korea conducted its first nuclear weapon test explosion in October 2006, the extensive network of sensors detected the relatively low-yield (0.6 kiloton) blast at 31 seismic stations in Asia, Australia, Europe, and North America.

No would-be cheater could be confident that a nuclear explosion that could possibly threaten U.S. security would escape detection. Although very low-yield nuclear tests cannot be detected with absolute certainty, countries that might be able to carry out such clandestine testing already possess advanced nuclear weapons and could add little, with additional testing, to the threats they already pose to the United States. Countries of lesser nuclear test experience and/or design sophistication would be unable to conceal tests in the numbers and yields required to develop advanced warheads. It is strongly in the U.S. interest to stop all other states from nuclear testing.

The CTBT would provide, for the first time, the option of short-notice, on-site inspections in response to signs of a suspicious event. In the event of a suspected nuclear explosion that cannot be resolved by remote sensing means, CTBT states may call for a short-notice, on-site inspection (OSI) of a suspected test site—an important deterrent against potential clandestine nuclear testing.

During the Senate debate in 1999, some critics complained that because the CTBT requires 30 of 51 nations on its Executive Council to agree to an on-site inspection, states unfriendly to the United States could block such inspections. In reality, the CTBT’s on-site inspection provisions were established to balance the need for rapid response to a suspected test against the possibility of “frivolous or abusive” inspections. The approval of 30 out of 51 members of the CTBTO’s Executive Council was designed to give nations like the United States confidence that OSIs would be approved as needed, but not by a small minority with questionable motives.

To protect national security interests unrelated to the inspections, states are allowed to restrict access to parts of the inspection area no larger than four square kilometers or a total of no more than 50 sq. km. However, if an inspected state restricts access, it must provide alternative ways for the inspection team to carry out its mission. If the bar for inspections had been set much lower, or if no allowances had been made for unrelated national security interests, one could imagine that there might be concerns in the Senate that CTBT on-site inspections could unduly infringe on U.S. sovereignty.

Ensuring compliance prior to entry into force. In 2019, the United States alleged that Russia, and perhaps China, are not adhering to its nuclear testing moratorium in a manner consistent with the ‘zero-yield’ standard outlined in the CTBT. The most effective way to resolve concerns about the potential for very low-yield nuclear explosions and enforce compliance with the CTBT is for the United States, China, and the other CTBT hold-out states to ratify the treaty and help bring it into force. When it does, states have the option to demand intrusive, short-notice on-site inspections. In the meantime, CTBT signatory states should engage in confidence-building activities as allowed for under the CTBT to resolve legitimate concerns.

Under Article VI of the treaty, which addresses the settlement of disputes before or after treaty entry into force, “the parties concerned shall consult together with a view to the expeditious settlement of the dispute by negotiation or by other peaceful means of the parties’ choice, including recourse to appropriate organs of this Treaty.” Such measures could, for instance, involve mutual confidence-building visits to the respective U.S. and Russian test sites by technical experts to address concerns about compliance.

Because the United States and Russia and China continue activities at their Cold War-era test sites, it is in their mutual interest, as well as the international community, to develop and implement transparency measures to increase confidence that no state is conducting low-yield explosions that are the result of a self-sustaining nuclear chain reaction.

The CTBT bans all nuclear test explosions. Some CTBT critics erroneously believe that because the treaty does not explictly define a "nuclear test explosion," some countries, such as Russia, consider hydronuclear tests (which are in fact very low-yield nuclear explosions) to be a "permitted" activity under the treaty.

In reality, the negotiating record of the treaty is clear. As documented in a series of CTBT fact sheets published by the State Department in September 2011, Russia and China and all of the other NPT nuclear weapon states have publicly affirmed publicly that the treaty’s Article I undertakings “not to carry out any nuclear weapons test explosion, or any other nuclear explosion” prohibit all nuclear test explosions, no matter what the yield.

“At the time the treaty opened for signature, all parties understood that the treaty was a “zero-yield” treaty as advocated by the United States in the negotiations,” according to a Sept. 28, 2011 fact sheet from the State Department’s Bureau of Arms Control, Verification and Compliance titled “Scope of the CTBT.”

As the State Department’s paper on “Key P-5 Public Statements on CTBT Scope” notes:

“Some countries prefer to use the term “no threshold,” meaning there is no line (or threshold) below which any amount of yield from a nuclear weapon test explosion would be allowed, and this usage is reflected in statements by senior P-5 government officials. The expression is translated into English in various ways: prohibition of ‘tests at whatever level,’ ‘without any threshold,’ ‘without threshold values,’ ‘regardless of the power,’ ‘any release of nuclear energy,’ or ‘regardless of the level.’ All of these formulations refer to the same concept: zero yield.”

Under this “zero-yield” interpretation, supercritical hydronuclear tests (which produce a self-sustaining fission chain reaction) are banned by the treaty, but subcritical hydrodynamic experiments, which do not produce a self-sustaining fission chain reaction, are permitted.


Entry Into Force of the CTBT

Though global support for the CTBT is widespread, formal entry into force requires that a specific group of 44 states named in Annex II of the treaty have ratified.

U.S. ratification of the CTBT is essential—but not sufficient—to win the support of the other remaining Annex II states needed for the treaty’s formal entry into force: China, Egypt, India, Iran, Israel, North Korea, and Pakistan.

China, which signed the CTBT in 1996, will also likely ratify if the United States does.

The prospect of U.S. ratification of the CTBT began to spur new thinking in India after the Obama administration stated it would pursue ratification of the treaty. In an August 30, 2009, interview in The Hindu, India’s then-National Security Advisor M. K. Narayanan said: “As of now, we are steadfast in our commitment to the moratorium. At least there is no debate in the internal circles about this.” Asked if India would have no problem signing the treaty if the others whose ratification is required for the CTBT to enter into force—especially China and the United States—did so, Mr. Narayanan responded: “I think we need to now have a full-fledged discussion on the CTBT. We’ll cross that hurdle when we come to it.”

Global support for early entry into force of the CTBT is strong.

In September 2016, the UN Security Council adopted resolution (2310) which reaffirms the global taboo against nuclear weapon test explosions and calls for ratification by the remaining eight Annex 2 hold-out states. The resolution also underscores the immense value of the Comprehensive Test Ban Treaty Organization's International Monitoring System, which effectively detects and deters clandestine nuclear testing even before entry into force.

UNSC resolution 2310, which is the first test ban-specific resolution considered by the Council, also recognizes the important September 15 statement from the permanent five members of the council reaffirming their legal commitment as CTBT signatories not to take any action that would “defeat the object or purpose of the treaty,” which is to halt “any nuclear weapon test explosion and any other nuclear test explosion.”

In September 2019, ministers of foreign affairs and diplomats representing nearly 50 countries gathered at the United Nations headquarters in New York City for the biannual the Article XIV conference, at which they expressed their support of the entry into force of the CTBT.

Until the CTBT enters into force, Article XIV of the treaty calls for a conference every two years, so that countries can continue to express support for the nuclear testing ban. These conferences demonstrate the worldwide support for the accord and desire for its immediate entry into force.

Algerian Foreign Minister Sabri Boukadoum, a co-president of the 2019 conference, called the treaty “a triumph” of international diplomacy that must be ratified by all parties who have not yet done so “as soon as possible.” Izumi Nakamitsu, undersecretary and high representative for disarmament affairs at the United Nations, said that there is “no substitute for the Comprehensive Nuclear Test Ban Treaty.”

U.S. ratification of the CTBT would also reinforce the taboo against testing and increase the costs for any state that might consider doing so. While it might be possible to sustain the voluntary moratoria undertaken by the nuclear testing states for some years, the risk of a resumption of testing by other nuclear weapons armed states will only grow over time. Also, concerns about clandestine nuclear testing might arise that could not be resolved in the absence of inspections provided for under the treaty. Failure to ratify the CTBT would increase uncertainty and weaken U.S. security.