Frequently Asked Questions
How is the NTI Nuclear Security Index developed?
The NTI Index is constructed to assess the state of nuclear security in countries around the world. The NTI Index development process is specifically designed to be rigorous and transparent and to embrace an international perspective. To develop the Index, NTI works closely with an International Panel of Experts to identify a set of indicators and subindicators that characterize a country’s nuclear security conditions. A slightly modified set of indicators and subindicators is used to assess countries in the Sabotage Ranking. The categories and indicators are weighted in a way that reflects their relative importance, as determined by NTI in conjunction with the International Panel of Experts.
The EIU leads the research process, taking advantage of its global network of analysts skilled in researching country laws and regulations. EIU analysts rely on public and open-source information, including national laws and regulations, government reports and public statements, and reports from non-governmental organizations and international organizations such as the IAEA. The NTI Index does not provide a facility-by-facility assessment of security practices. More detailed information is available in the full methodology appendix prepared by the Economist Intelligence Unit (EIU) and is available for download.
NTI prioritizes openness throughout the Index process. The 22 governments that have weapons-usable nuclear materials and the 25 governments that do not but that are included in the Sabotage Ranking were offered the opportunity to review and comment on preliminary results to ensure that the NTI Index reflects the most accurate and up-to-date information possible. Of the 46 countries and Taiwan, 26 took advantage of this opportunity.
What is the Theft Ranking?
The “Theft Ranking” refers to two rankings that assess nuclear materials security conditions with respect to the risk of theft of weapons-usable nuclear materials for (a) 22 countries with one kilogram or more of weapons-usable nuclear materials and (b) 154 countries with less than one kilogram of or no weapons-usable nuclear materials all. Countries without weapons-usable nuclear materials are included because they have a responsibility to ensure that they do not serve as safe havens, staging grounds, or transit routes for illicit nuclear activities. The 2012 and 2014 editions of the NTI Index included only these two Theft Rankings. The Sabotage Ranking was added for the first time in the 2016 NTI Index, alongside the third edition of the Theft Ranking. The 2018 NTI Index continues to include both.
What are weapons-usable nuclear materials?
For purposes of the Theft Ranking, the term “weapons-usable nuclear materials” includes highly enriched uranium (HEU), which is uranium enriched to 20 percent or more in the isotope U-235 (including spent fuel); separated plutonium, which is plutonium separated from irradiated nuclear fuel by reprocessing; and the plutonium content in fresh mixed oxide fuel, which consists of blended uranium and plutonium that can be used to fuel nuclear power plants.
What does the Theft Ranking assess?
The Theft Ranking assesses nuclear materials security conditions with respect to the theft of weapons-usable nuclear materials that could be used to build a nuclear device. The Theft Ranking does not assess security for low-enriched uranium or for the radiological materials needed to build a “dirty bomb,” nor does it assess proliferation risks or disarmament. All of those areas are critical and must also be addressed by governments. The Theft Ranking for countries with weapons-usable nuclear materials assesses countries against a broad framework of five categories with 20 indicators and 61 subindicators. The Theft Ranking for countries without weapons-usable nuclear materials assesses countries against only three categories with 9 indicators and 27 subindicators. Indicators reflect policies, actions, and other conditions that shape a state’s overall nuclear materials security.
What changes have been made to the Theft Ranking since the 2016 edition?
Since the 2016 NTI Index, minimal changes have been made to the Theft Ranking. Specifically, a subindicator was added to the Cybersecurity indicator to assess whether countries require nuclear facilities to develop a cyber-incident response plan. In addition, because Argentina and Poland removed all of their weapons-usable nuclear materials since the previous edition of the NTI Index, both countries moved from the ranking of countries with materials to the ranking of countries without materials. The ranking for countries with materials now has 22 countries, and the ranking for countries without materials now has 154 countries. For more information on those changes, see the full EIU Methodology.
If the Theft Ranking has changed, how are scores compared across years?
To allow for accurate year-over-year comparisons so that progress may be tracked even when the Index framework has been updated, the EIU rescores countries in prior editions of the NTI Index using the updated framework and the data that would have been available when research for each respective edition was conducted. Additional review and research of scores from prior editions also is conducted on an as-needed basis.
What is the Sabotage Ranking?
The “Sabotage Ranking” assesses the nuclear security conditions of 44 countries and Taiwan with nuclear facilities, the sabotage of which could result in a dangerous release of radiation that could cause serious health consequences. All 44 countries and Taiwan also are included in one of the two versions of the Theft Ranking—20 have one kilogram or more of weapons-usable nuclear materials, and 24 countries and Taiwan have less than one kilogram of or no weapons-usable nuclear materials.
What does the Sabotage Ranking measure?
The Sabotage Ranking measures nuclear security conditions with respect to the sabotage of nuclear facilities. For purposes of the NTI Index related to sabotage, nuclear facilities are defined as those facilities, the sabotage of which could result in a dangerous release of radiation. They include (a) operating nuclear power reactors or nuclear power reactors that have been shut down within the past five years, (b) research reactors with a capacity of two megawatts or greater, (c) reprocessing facilities, and (d) spent fuel pools only if the fuel has been discharged in the past five years and if not associated with an operating reactor.
The Sabotage Ranking assesses countries against five categories with 16 indicators and 52 subindicators. Indicators reflect policies, actions, and other conditions that shape a country’s overall nuclear security. A more detailed description of scoring criteria and sources is available in the full EIU Methodology.
What are the differences between the Theft Ranking and the Sabotage Ranking?
Because security measures to protect nuclear facilities and to protect materials against theft and sabotage often are related, NTI and the EIU—with input from the International Panel of Experts and technical advisors—looked at the framework for the Theft Ranking to determine which indicators and subindicators would be relevant to sabotage in their current format, which indicators and subindicators would need to be edited or deleted, and whether the Sabotage Ranking should include any new indicators and subindicators that are relevant to sabotage but not theft. As a result of that analysis, 14 subindicators from the Theft Ranking were not included, and 5 subindicators were added.
What changes have been made to the Sabotage Ranking since 2016?
Because both the Theft and Sabotage Rankings evaluate cybersecurity, the Sabotage Ranking also is affected by the minor update made to indicator 2.5 Cybersecurity. Specifically, a subindicator was added to measure whether countries require nuclear facilities to develop a cyber-incident response plan.
If the Sabotage Ranking has changed, how are comparisons made across years?
To allow for accurate year-over-year comparisons so that progress may be tracked even when the Index framework has been updated, the EIU rescores countries in prior editions of the NTI Index using the updated framework and the data that would have been available when research for each respective edition was conducted. Additional review and research of scores from prior editions is also conducted on an as-needed basis.
How are scores calculated, and what do they mean?
The overall score (0–100) for each country in the NTI Index is a weighted sum of the categories. Each category is scored on a scale of 0–100, where 100 represents the most favorable nuclear security conditions, and 0 represents the least favorable security conditions in the NTI Index. The subindicator scores (ranging from 0 to 8, depending on the question) are summed to determine the indicator score. Each category is normalized on a scale of 0–100 on the basis of the sums of underlying indicator scores, and a weight is then applied. How each category is weighted is based on input from the International Panel of Experts and reflects the relative importance and relevance of each category and indicator. A score of 100 in the NTI Index does not indicate that a country has perfect nuclear security conditions, and a score of 0 does not mean that a country has no security; instead, the scores of 100 and 0 represent the highest and lowest possible scores, respectively, as measured by the NTI Index criteria.
How was the data gathered?
The EIU employed country experts and regional specialists from its global network of more than 350 analysts and contributors around the world. Most of the research was conducted between October 2017 and April 2018, although data were updated as late as June 15, 2018, as new information became available. Therefore, actions taken by countries after June 15, 2018, are not captured in this edition of the NTI Index.
What types of information were used to score countries?
In creating the NTI Index, the EIU relied on publicly available sources, including (a) primary legal texts and legal reports; (b) government publications and reports; (c) academic publications and reports; (d) websites of government authorities, international organizations, and non-governmental organizations; (e) interviews with experts; and (f) local and international news media reports. In addition, the EIU proprietary country rankings and reports (specifically “Risk Briefing” and the “Business Environment Ranking”) were used to score indicators in the Risk Environment category. Governments provided additional information in response to data review and confirmation requests.
The NTI Index does not provide a facility-by-facility assessment of security practices, and neither the EIU nor NTI conducts research at facilities. Although facility-level assessments would provide important “ground truth” information, such information currently is not available because of the sensitive nature of specific security arrangements.
In the cases of Iran, Israel, North Korea, and Pakistan, publicly available information is lacking. However, because those countries rely on military (or, in the case of Israel, civil defense force) protection for nuclear sites, scores were assigned using a proxy indicator: military capability or sophistication. In some cases, scores relied on expert input or other secondary expert sources. For a detailed description of how challenging countries were scored, see the full EIU Methodology.
Does the NTI Index account for recent initiatives such as those involving Iran and North Korea?
The NTI Index’s scope is limited to assessing the nuclear security conditions within a country to prevent the theft of weapons-usable nuclear materials, as well as the sabotage of nuclear facilities. It does not consider measures to prevent the proliferation of nuclear materials or technologies. As a result, nuclear non-proliferation initiatives such as the Joint Comprehensive Plan of Action or the recent bilateral engagement between the United States and North Korea do not directly affect countries’ scores in the NTI Index.
Were governments consulted during the development of the NTI Index?
All countries in the Theft and Sabotage Rankings were offered briefings on the NTI Index at the beginning of the process. In addition, after researching and gathering data, NTI and the EIU provided the 46 countries and Taiwan with an opportunity to review and comment on the EIU’s preliminary results. The purpose of this data review and confirmation process was to ensure the accuracy of the 2018 NTI Index data, given that much of the research involves subjects for which information is not always publicly available. Thirteen countries with one kilogram or more of nuclear materials in the Theft Ranking and 23 countries and Taiwan in the Sabotage Ranking participated in the data confirmation process.
What other experts were consulted during the development of the NTI Index?
NTI and the EIU received input from the International Panel of Experts. In addition to the international panel, technical advisors were consulted.
Where can I find all of the scores and data?
All information is available on this website and in the Excel files for download. The scores for indicators and subindicators in both versions of the Theft Ranking and in the Sabotage Ranking are included in three models that are available as Excel workbooks. The models offer a wide range of analytic tools, thereby allowing a deeper investigation of measures of nuclear security globally. Users can filter countries by region, for example, or by membership of international organizations or multilateral initiatives. Users can compare any two countries directly and can examine correlations between indicators. Individual country profiles are also included in the models, thus permitting a deeper dive into the nuclear security conditions in a given country.
In the Score Simulator, the weights assigned to each indicator can be changed to reflect different assumptions about the importance of categories and indicators. A user can also change individual subindicator scores to see how a country’s overall scores would have been different if, for example, it had ratified a treaty or taken some other action captured in the NTI Index. Finally, the model allows the final scores to be benchmarked against external factors that may potentially influence nuclear security.
 Argentina, Australia, Belarus, Belgium, Canada, Chile, the Czech Republic, Finland, France, Germany, Hungary, Italy, Japan, Mexico, the Netherlands, Norway, Peru, Romania, Slovenia, South Korea, Sweden, Switzerland, Taiwan, the United Kingdom, Ukraine, and the United States.
 The threshold of one kilogram takes into account the International Atomic Energy Agency’s INFCIRC/225, Rev. 5, which states that quantities greater than one kilogram of HEU should be afforded higher levels of protection. NTI recognizes that some states may have gram quantities of weapons-usable nuclear materials in multiple locations that, added together, may bring totals to more than one kilogram. For purposes of the Theft
 One exception is the input from a single country, which submitted information for data confirmation in July 2018.
 Countries with weapons-usable nuclear materials that participated in the data confirmation process include: Australia, Belarus, Belgium, Canada, France, Germany, Italy, Japan, the Netherlands, Norway, Switzerland, the United Kingdom, and the United States. Countries with nuclear facilities at risk of dangerous radiation releases that participated in the data confirmation process include: Argentina, Australia, Belgium, Canada, Chile, the Czech Republic, Finland, France, Germany, Hungary, Japan, Mexico, the Netherlands, Norway, Peru, Romania, Slovenia, South Korea, Sweden, Switzerland, Ukraine, the United Kingdom, and the United States.