11/01/2024 30min.

Russia’s Withdrawal From Ratification Of The Comprehensive Nuclear-Test-Ban Treaty (CTBT) In Context


President Vladimir Putin’s November signatrure of the law for Russia’s withdrawal from ratification of the Comprehensive NuclearTest-Ban-Treaty (CTBT) will further complicate the entry into force of this important nuclear disarmament treaty. This reflection places the decision in the treaty framework of international efforts to achieve a permanent ban on all nuclear tests. Increased attention is given to the CTBT, its International Monitoring System (IMS) for verification, and the difficulties associated with the entry into force of the treaty. In this context, the reflection also mentions the problems of the treaty ratification in the US.

Nuclear testing has resulted in, among other things, serious health problems and premature deaths of people exposed to it, and has also damaged the environment. These tests are also one of the main obstacles to preventing the proliferation of nuclear weapons and achieving their total destruction. As stated in the conclusions of the reflection, the withdrawal and its justification can also be seen as yet another manifestation of Russia’s efforts to bring a balance to the asymmetry between the country’s security position and that of the US, which has not ratified the CTBT.


Nuclear weapon tests verify theoretical calculations of the nuclear charge and the fission reaction process. If a non-nuclear-weapon state makes a political decision to initiate a nuclear military programme, the tests help it to publicly demonstrate its successful completion. In particular, they enable nuclear-weapon states to improve the quality of nuclear warheads and their delivery systems by, inter alia, verifying the combat performance of nuclear explosive delivery systems in different environments. The ban on nuclear testing has been described as a global security measure towards preventing nuclear proliferation and achieving nuclear disarmament.

From 1945 to the adoption of the CTBT in 1996, the major nuclear weapon states conducted around 2,000 nuclear tests in various environments. The US (1,054), the Soviet Union (715), France (210), the UK (45) and the PRC (45) have conducted the most tests After the adoption of the CTBT, only India and Pakistan conducted nuclear tests in 1998 and North Korea conducted six tests in the period from 2006 to 2017. In recent years, all nuclear-weapon countries have respected the unwritten moratorium on such tests and have not conducted them.


The international community’s efforts to end nuclear testing have been echoed by the adoption of two major international treaties devoted exclusively to its prohibition. These are the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in the Outer Space and Undr Water and the 1996 Comprehensive Nuclea-Tes-Ban Treaty. Unlike the first treaty, which is still in force but nevertheless allows underground nuclear testing, the second treaty prohibits it in all environments. At the same time, it establishes an effective global verification system. However, it has not yet entered into force.

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) is also generally in favour of supporting a nuclear test ban, while the Treaty on the Prohibition of Nuclear Weapons (TPNW) is more explicit on this issue. The treaties establishing multilateral nuclear-weapon-free zones in populated areas also contain such a ban. The zones are five in number and include over a hundred countries in Africa (the Treaty of Pelindaba), Latin America and the Caribbean (the Treaty of Tlatelolco), Central Asia (the Treaty of Semipalatinsk), Southeast Asia (the Treaty of Bangkok) and the South Pacific (the Treaty of Rarotonga). Individually established nuclear-free zones, such as Mongolia, also subscribe to the nuclear test ban.


This treaty is better known as the Partial Test Ban Treaty (PTBT) and is temporarily in force.
It was concluded between the US, the Soviet Union and the UK in 1963, but in the following years it became multilateral. It bans nuclear testing in three types of environments but allows testing underground. Its implementation was initially verified mainly by national technical means. However, with the subsequent construction and current operational functionality of the International Monitoring System (IMS), in connection with the adoption of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 1996, the means of verifying compliance with the PTBT have become much more effective. The Treaty has still not been signed by France and the PRC.

Following the PTBT, the US and the Soviet Union concluded the Threshold Test Ban Treaty (TTBT) in 1974. The treaty set a nuclear test explosive threshold of 150 kilotons (kt) of conventional trinitrotoluene equivalent (TNT). By comparison, the “Hiroshima” bomb had an approximate explosive yield of 15 kt of TNT. However, as a result of various disagreements between the signatory countries, including on the method of verification of treaty performance, the TTBT did not enter into force until 1990.


The CTBT was negotiated at the Conference on Disarmament in Geneva. Due to the difficulties in its approval amd the need to secure a consensus, several countries, notably Australia, New Zealand and Mexico, produced the initiative to move the approval process to the plenary of the UN General Assembly, where the mentioned condition does not apply. The treaty was thus approved by a majority vote in 1996.
The Treaty prohibits “any nuclear weapon test explosion or any other nuclear explosion”.

The Treaty’s organisation consists of the Conference of Member States, the Executive Council and the Technical Secretariat. The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO Preparatory Commission, hereafter referred to as the Commission) was established at a meeting of the signatory states convened by the UN Secretary-General in November 1996. The Commission’s activities are focused on promoting the acceleration of the entry into force of the CTBT and the establishment of the IMS verification system.

The IMS is an integral and effective part of the contract verification process. It is already in its final stages, and when completed, it will consist of 321 monitoring stations and 16 radionuclide laboratories. Its seismographs can detect the characteristics of a nuclear explosion, even at extremely low intensities, and can distinguish nuclear explosions from non-nuclear explosions such as chemical and mining explosions, earthquakes and meteorite falls. Depending on the methods used to detect the characteristics and locations of the explosion, the system consists of 50 primary and 120 auxiliary seismological stations for underground monitoring, 11 hydroacoustic stations for underwater monitoring, 60 infrasonic stations for atmospheric monitoring and 80 radionuclide stations for detecting radioactive dust coming from possible nuclear explosions in the atmosphere or leaked from underground or underwater nuclear explosions. These stations are also located in remote and inaccessible locations around the globe. Once the CTBT enters into force, on-site inspections will also be part of the IMS. Several international exercises have already been conducted to test the inspection methods and procedures and also to test their functionality and effectiveness. The evaluation of the exercise results demonstrated the effectiveness of the on-site inspection methods, including the technical means used. The success of the existing monitoring system was also successfully verified by its reliable detection of a relatively weak nuclear test explosion (0.6 kt TNT) carried out by the DPRK in 2006.

The IMS is supported by the Vienna-based International Data Centre (IDC), where the measured data are collected, analysed and archived after their transmission via the Global Communications Infrastructure (GCI) from the individual stations. The IDC has been providing IMS results and data to signatory states on a test basis since 21 February 2000. The IMS can also play an important role by participating in the warning system for the prevention of natural disasters such as tsunamis or earthquakes.

Once the Treaty enters into force, its duration will be unlimited. It is envisaged that review conferences will be convened at ten year intervals to assess the implementation and effectiveness of the Treaty. Biennial conferences of the signatory countries are cuttently held on the issue of ensuring the entry into force of the Treaty. After entry into force, the new treaty would replace the above-mentioned PTBT. In terms of nuclear disarmament efforts, a shortcoming of the CTBT is the absence of a ban on nuclear weapons research and development and so-called subcritical testing. The UN SG is the depositary of the treaty.

The entry into force of the Treaty is conditional upon its ratification by 44 States, namely those listed in Annex 2 of Treaty Article XIV. These are states that participated in the negotiation of the treaty and have some nuclear capabilities, e.g. in terms of energy or research. Eight states have long refused to ratify the Treaty. Of these, three (India, the DPRK and Pakistan) have not signed it and the remaining five (the PRC, Egypt, Iran, Israel and the US) have signed it but not ratified it. Russia ratified it on 30 June 2000. Its withdrawal from the ratification in Novembe, brought the number of countries refusing to ratify the Treaty to nine.

On the initiative of Kazakhstan, a UN General Assembly resolution (A/RES/64/35) was adopted in 2009, which declared 29 August as the International Day against Nuclear Tests. On that day in 1991, the dismantling of a nuclear test site in the then Soviet Union, namely in Semipalatinsk, Kazakhstan, was completed. The aim of the holiday is to remind the world community of the devastating effects of nuclear testing on human life and health and the environment and also to draw attention to the urgency of the treaty’s entry into force.


The NPT was negotiated in 1968 and entered into force in 1970. It has near-universal membership and is based on three pillars, which are the peaceful uses of nuclear energy, nuclear non-proliferation, and a vague commitment by the parties, particularly the nuclear powers, to nuclear and general disarmament (Article VI). The treaty legalises the possession of nuclear weapons by the five permanent members of the Security Council, the so-called P5 (the US, Russia, France, the PRC and the UK), while strictly prohibiting any activities by the other non-nuclear-weapon states with the aim to acquire these types of weapons. Four nuclear-weapon states (India, Pakistan, Israel and the DPRK) are not state partiess to the treaty.

In its treaty text, the nuclear test ban is mentioned only in the preambular part. It recalls, among other things, the decision of the parties to the PTBT “to seek to achieve the discontinuance of all test explosions of nuclear weapons for all time and to continue negotiations to this end”.


The TPNW was adopted at the 2017 UN Conference in New York and entered into force in January 2021. All nine nuclear-weapon countries and most of their allies and partners, however, refused to support the TPNW and this negative attitude toward it on their part continues. In relation to the CTBT, the preambular part of the TPNW treaty “recognizes the vitall importance of the Comprehensive Nuclear-Test-Ban Treaty and its verification regime as a core element of the nuclear disarmament and non-proliferation regime”. The prohibition of nuclear testing is contained in Article 1(a), undrr which each State Party underlines never to “develop, test, produce, manufactureo, othervise acquirie, possess or stockpile nuclear weapons or other nuclear explosive devices”. The use and the testing of nuclear weapons are dealt with in the unprecedented Article 6, which provides for assistance to victims of these activities, including reducing their negative environmental impacts.


Following the Russian State Duma’s approval of the CTBT deratification law, the related document was signed by President Vladimir Putin on 2 November 2023. The adoption of the law was justified by the United States’ failure to ratify the treaty to date and the reconstruction activities at the US nuclear test site in Nevada. In the context of the deratification, the Russian leadership simultaneously confirmed the maintenance of the national moratorium on nuclear testing, which Russia would only withdraw from if the US resumed such testing. The operational functionality of the IMS verification system monitoring stations located on the Russian territory will also continue.

The international legal aspects of the Russian deratification are the subject of an article entitled “Russia, the CTBT and International Law,” published in November 2023 by the prestigious US non-governmental organization called the Arms Control Association (ACA). Its author is David A. Koplow, a Scott K. Ginsberg Professor of Law at the Georgetown University Law Center. In his analysis, he first rules out the possibility of applying the CTBT’s Article IX treaty provision speaking of the “supreme national interest withdrawal clause” to Russia’s justification for the deregulation because the treaty is not yet in force.

As he goes on to argue, Article 18(a) of the 1969 Vienna Convention on the Law of Treaties (the Vienna Convention), which sets out two circumstances in which a state is obliged to “refrain from acts which would defeat the object and purpose of a treaty” before the treaty enters into force, also cannot be clearly used to justify the Russian move. In this regard, the author points to the 2016 Joint Statement of the five permanent members of the UN Security Council, the so-called P5, in which they authoritatively affirmed that a nuclear test would nullify the object and purpose of the CTBT, as an argument precluding the application of that article. Moreover, the P5 Statement was subsequently endorsed by the entire Security Council with Resolution 2310. Another of his arguments is that Russia had not made it clear that its position on deratification was an irreversible position when the law on deratification was passed. The author thus concludes that considering past practices, the “withdrawal of ratification most likely has no practical legal effect“. In the author’s view, the UN GT, as a treaty depositary, can probably be expected to accept it. He concludes that the US and Russia, in their capacity as signatories to the CTBT, are obliged to comply with the object and purpose of the treaty, i.e. including not conducting nuclear tests.


The first politician to sign the CTBT was US President Bill Clinton in September 1996. After failing to win a two-thirds support (67 votes) for this among the onee hundred members of the US Senate in 1999, President Clinton instructed the retired General John Shalikashvili, a former Chairman of the Joint Chiefs of Staff, to negotiate with the Republican Senators in order to overcome their objections. In January 2001 the General sent a report to President Clinton that, among other things, demonstrated the reliability of the IMS and thereby refused the main arguments of its critics, e.g., those about the potential for circumvention of the monitoring system. In an accompanying letter Gen. Shalikashvili stated, among other things, that “the Treaty is a very important part of the global non-proliferation efforts and is compatible with keeping a safe reliable U.S. nuclear deterrent”. However, the General‘s efforts were not successful.

Most Republican senators continue to express doubts on the issue and refuse to support ratification. In addition to reservations about the effectiveness of the IMS, the critical arguments include concerns about reducing the US technological superiority and threatening the programme that ensures the safety and maintenance of stored nuclear weapons. The difference between the two political parties in their approach to the issue is also documented by relevant passages in the Trump and Biden administrations’ nuclear strategies, i.e. the Nuclear Posture Review (NPR). While Trump’s 2018 NPR is clearly opposed to CTBT ratification, Biden’s 2022 NPR supports it. According to a May 22, 2020 article in The Washington Post, under the former administration, a meeting of US national security officials considering the possibility of resuming nuclear testing took place in mid-May 2020. The rationale was the unproven accusation against Russia and China in which they were accused of conducting low explosive nuclear tests. Earlier, several Republican senators petitioned the administration to revoke the U.S. signature of the CTBT.


The signing of the law on Russia’s withdrawal from ratification of the CTBT by President Putin in early November 2023 can be described as yet another step by the Russian leadership toward reducing the asymmetry between the country’s security position and that of the US, which has never ratified the treaty. A similar step was the 2022 decision to deploy Russian tactical nuclear weapons in Belarus as a counterweight to the long-term deployment of US tactical nuclear weapons in five allied European countries.

The current internal political polarisation in the US and the continued rejectionist stance of the Republican Party towards the ratification of the CTBT do not give much hope for a positive turn in the near future. It can therefore be assumed that no change in the positions of Russia and China on this issue can be expected in the foreseeable future. In the context of the overall deterioration of the security situation in the world, the fact that reconstruction activities are underway at the nuclear test polygons of the US, Russia and China for the possible resumption of nuclear tests is a worrying phenomenon. However, under international law, the resumption of nuclear testing by these nuclear signatory countries should be preceded by a revocation of their treaty signatures. However, this has not yet happened. Nevertheless, the current state of play on this issue reinforces the dangerous and risky spiral towards a nuclear arms race. The accompanying phenomenon
is the enormous increase in arms spending and the growing influence of the militaryindustrial complex.

The practice to date of most nuclear-weapon states, which have either not signed or not ratified the Treaty, namely that of dealing with the situation by declaring an annual moratorium on nuclear testing is certainly to be commended. However, it cannot be an equivalent substitute for membership in a legally binding verification and implementation treaty instrument. At the various forums on nuclear weapons issues, their final reports usually include a call for all countries that have not yet ratified the Treaty to approve its ratification as soon as possible to allow its entry into force. The Czech Republic has also long supported such efforts.