Comprehensive Nuclear Test Ban Treaty

International Legal Research

Information about Comprehensive Nuclear Test Ban Treaty in free legal resources:

Treaties & Agreements

International Organizations

Jurisprudence $ Commentary

European Union

IP Law


Comprehensive Nuclear Test Ban Treaty

Comprehensive Nuclear Test Ban Treaty in 2011

United States views on international law (based on the document “Digest of U.S. Practice in International Law”): In her May 10 address to the Arms Control Association, Ms. Tauscher also discussed the Comprehensive Nuclear Test Ban Treaty (“CTBT”). That portion of her speech is excerpted below; the full text is available at (internet link) For background on the Obama administration's determination to seek ratification of the CTBT, see this world legal encyclopedia in relation with the year 2009 at 764-66.

…[L]et me turn to the Comprehensive Test Ban Treaty. President Obama vowed to pursue ratification and entry into force of the CTBT in his speech in Prague. In so doing the United States is once again taking a leading role in supporting a test ban treaty just as it had when discussions first began more than 50 years ago.

As you know, in the aftermath of the Cuban Missile Crisis, the United States ratified the Limited Test Ban Treaty, which banned all nuclear tests except those conducted underground.…

In the months after the crisis, President Kennedy used his new found political capital and his political skill to persuade the military and the Senate to support a test ban treaty in the hopes of curbing a dangerous arms race. He achieved a Limited Test Ban Treaty, but aspired to do more. Yet, today, with more than 40 years of experience, wisdom, and knowledge about global nuclear dangers, a legally binding ban on all nuclear explosive testing still eludes us.


In the U.S. engagement with the Senate, we want to leave aside the politics and explain why the CTBT will enhance the U.S. national security. the U.S. case for Treaty ratification consists of three primary arguments.

One, the United States no longer needs to conduct nuclear explosive tests, plain and simple. Two, a CTBT that has entered into force will obligate other states not to test and provide a disincentive for states to conduct such tests. And three, we now have a greater ability to catch those who cheat.

Let me take these points one by one.

From 1945 to 1992, the United States conducted more than 1,000 nuclear explosive tests—more than all other nations combined. The cumulative data gathered from these tests have provided an impressive foundation of knowledge for us to base the continuing effectiveness of the U.S. arsenal. But historical test data alone is insufficient.

Well over a decade ago, we launched an extensive and rigorous Stockpile Stewardship program that has enabled the U.S. nuclear weapons laboratories to carry out the essential surveillance and warhead life extension programs to ensure the credibility of the U.S. deterrent.

Every year for the past 15 years, the Secretaries of Defense and Energy from Democratic and Republican Administrations, and the directors of the nuclear weapons laboratories have certified that the U.S. arsenal is safe, secure, and effective. And each year they have affirmed that we do not need to conduct explosive nuclear tests.


When it comes to the CTBT, the United States is in a curious position. We abide by the core prohibition of the Treaty because we don't need to test nuclear weapons. And we have contributed to the development of the International Monitoring System. But the principal benefit of ratifying the Treaty, constraining other states from testing, still eludes us. That doesn't make any sense to me and it shouldn't make any sense to the Members of the Senate.

I do not believe that even the most vocal critics of the CTBT want to resume explosive nuclear testing. What they have chosen instead is a status quo where the United States refrains from testing without using that fact to lock in a legally binding global ban that would significantly benefit the United States.

Second, a CTBT that has entered into force will hinder other states from advancing their nuclear weapons capabilities. Were the CTBT to enter into force, states interested in pursuing or or incur international condemnation and sanctions for testing.

While states can build a crude first generation nuclear weapon without conducting nuclear explosive tests, they would have trouble going further, and they probably wouldn't even know for certain the yield of the weapon they built. More established nuclear weapons states could not, with any confidence, deploy advanced nuclear weapon capabilities that deviated significantly from previously tested designs without explosive testing.

Nowhere would these constraints be more relevant than in Asia, where you see states building up and modernizing their forces. A legally binding prohibition on all nuclear explosive testing would help reduce the chances of a potential regional arms race in the years and decades to come.

Finally, we have become very good at detecting potential cheaters. If you test, there is a very high risk of getting caught. Upon the Treaty's entry into force, the United States would use the International Monitoring System to complement the U.S. own state of the art national technical means to verify the Treaty.

In 1999, not a single certified IMS station or facility existed. We understand why some senators had doubts about its future, untested capabilities. But today the IMS is more than 75 percent complete. 254 of the planned 321 monitoring stations are in place and functioning. And 10 of 16 projected radio-nuclide laboratories have been completed. The IMS detected both of North Korea's two announced nuclear tests.

While the IMS did not detect trace radioactive isotopes confirming that the 2009 event was in fact a nuclear explosive test, there was sufficient evidence to support an on-site inspection. On-site inspections are only permissible once the Treaty enters into force. An on-site inspection could have clarified the ambiguity of the 2009 test.

While the IMS continues to prove its value, the U.S. national technical means remain second to none and we continue to improve them. Last week, the U.S. colleagues at the NNSA conducted the first of a series of Source Physics Experiments at the Nevada Nuclear Security Site. These experiments will allow the United States to validate and improve seismic models and the use of new generation technology to further monitor compliance with the CTBT. Senators can judge the U.S. overall capabilities for themselves by consulting the National Intelligence Estimate released last year.

Taken together, these verification tools would make it difficult for any state to conduct nuclear tests that escape detection. In other words, a robust verification regime carries an important deterrent value in and of itself. Could we imagine a far-fetched scenario where a country might conduct a test so low that it would not be detected? Perhaps. But could a country be certain that it would not be caught? That is unclear. Would a country be willing to risk being caught cheating? Doubtful, because there would be a significant cost to pay for those countries that test.

More about the Issue

We have a strong case for Treaty ratification. In the coming months, we will build upon and flesh out these core arguments. We look forward to objective voices providing their opinions on this important issue. Soon, the National Academy of Sciences, a trusted and unbiased voice on scientific issues, will release an unclassified report examining the Treaty from a technical perspective. The report will look at how U.S. ratification would impact the U.S. ability to maintain the U.S. nuclear arsenal and the U.S. ability to detect and verify explosive nuclear tests.

Let me conclude by saying that successful U.S. ratification of the CTBT will help facilitate greater international cooperation on the other elements of the President's Prague Agenda. It will strengthen the U.S. leverage with the international community to pressure defiant regimes like those in Iran and North Korea as they engage in illicit nuclear activities. We will have greater credibility when encouraging other states to pursue nonproliferation objectives, including universality of the Additional Protocol.

On June 1, 2011, Rose Gottemoeller, Assistant Secretary of State for Arms Control, Verification, and Compliance, delivered remarks to the CTBT Organization in Vienna, Austria. Excerpts below from Ms. Gottemoeller's speech relate to U.S. participation in CTBT activities even prior to ratification by the U.S. The full text of Ms. Gottemoeller's remarks is available at (internet link)

As the Administration engages the U.S. Senate the United States has increased its participation in all of the Preparatory Commission's activities in preparation for the entry into force of the CTBT, especially with respect to the effective implementation of the Treaty's verification regime. U.S. technical experts are working closely with their counterparts from the Provisional Technical Secretariat and with other experts from many Signatory States represented here today in collaborative efforts to improve the capabilities of the global International Monitoring System and the International Data Centre.

After an eight-year absence, U.S. experts since 2009 have been fully engaged in further developing the On-Site Inspection element of the verification regime, both from policy and technical perspectives. The United States has also continued to bear the full costs of operating, maintaining, and sustaining the 31 stations of the International Monitoring System assigned by the Treaty to the United States. These actions tangibly demonstrate the commitment of the United States to prepare for the entry into force of this Treaty.

While much has been accomplished, more hard work lies ahead. We need to maintain the momentum towards completion and maintenance of a fully functioning verification system. Such a system, meeting the requirements established by the PrepCom, serves as a strong deterrent for any State Party contemplating a nuclear test. Demonstrating that the Treaty can be verified also supports the argument that it should be ratified, and helps build further momentum for the Treaty's entry into force.

Comprehensive Nuclear Test Ban Treaty in 2011

United States views on international law (based on the document “Digest of U.S. Practice in International Law”): On December 6, 2011, the State Department issued a press statement by Secretary Clinton welcoming Indonesia's ratification of the CTBT. Her statement repeated the commitment to seek U.S. Senate advice and consent to ratification of the CTBT and urged other states that have not yet ratified to join. Secretary Clinton's statement is available at (internet link)

Comprehensive Nuclear Test Ban Treaty in 2013

United States views on international law [1] in relation to Comprehensive Nuclear Test Ban Treaty: On September 27, 2013, the States Signatories to the Comprehensive Nuclear Test Ban Treaty (“CTBT”) met in New York for a conference held in accordance with Article XIV of the Treaty to discuss concrete measures to facilitate the entry into force of the CTBT. The Final Declaration of the conference is available at (link resource) The statement of the United States, as delivered at the conference, is excerpted below and also available at (link resource)

Some Aspects of Comprehensive Nuclear Test Ban Treaty

In June of this year, President Obama reaffirmed that “we will work to build support in the United States to ratify the Comprehensive Nuclear-Test-Ban Treaty.” The President's words in Berlin underscore our policy, as stated in the 2010 Nuclear Posture Review, that “ratification of the CTBT is central to leading other nuclear weapons states toward a world of diminished reliance on nuclear weapons, reduced nuclear competition, and eventual nuclear disarmament.” The United States has observed a moratorium on nuclear explosive testing since 1992. Hence, even before the completed negotiation of the CTBT, the United States was in compliance with what would become the central prohibition of the treaty.


Furthermore, with a global ban on nuclear explosive tests in place, states interested in pursuing or advancing their nuclear weapons programs would have to either risk deploying weapons with uncertain effectiveness or face international condemnation, and possible sanctions, for conducting nuclear explosive tests.


A CTBT that has entered into force would further benefit national and international security by facilitating greater international cooperation on other arms control and nonproliferation priorities.


In the 17 years since the Treaty was opened for signature, the Provisional Technical Secretariat (PTS), and the States Signatories have made great strides in building out the Treaty's verification regime. What was, nearly two decades ago, just a concept is now a nearly complete International Monitoring System (IMS) that has effectively demonstrated its capabilities under real-world conditions, detecting and helping states identify the three nuclear explosive tests conducted by North Korea over the past several years. In addition, following the Fukushima nuclear crisis, we saw how the IMS can be useful for non-verification related purposes, such as tsunami warnings and tracking radioactivity from reactor accidents.


In addition, the On-Site Inspection (OSI) element has developed into a useful tool that will be capable of conducting robust and effective inspections at entry into force. Next year's Integrated Field Exercise, to be held in Jordan, is poised to demonstrate that capability and help ensure that an OSI capability is ready to go as soon as the Treaty enters into force.


See Also

  • Use Of Force
  • Arms Control
  • Disarmament
  • Nonproliferation
  • Nuclear Nonproliferation
  • Nuclear Ban
  • Treaties



  1. Comprehensive Nuclear Test Ban Treaty in the Digest of United States Practice in International Law

Leave a Comment