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SDG16.4 and the collection of data on illicit arms flows: Progress made but challenges ahead

A cache of weapons is assembled on the deck of the guided-missile destroyer USS Gravely (DDG 107).
A cache of weapons is assembled on the deck of the destroyer USS Gravely. The weapons were seized from a stateless dhow which was intercepted by the coastal patrol ship USS Sirocco (PC 6) on March 28, 2016.



On 18 June states and NGOs will meet in New York for the Third Review Conference of the UN Programme of Action (POA) on Small Arms and Light Weapons (SALW). Among the many issues that stakeholders will be addressing during the 2 week meeting will be the generation of data for measuring the attainment of target 16.4 of the Sustainable Development Goals (SDGs). SDG 16.4 commits states to inter alia significantly reduce illicit arms flows by 2030 and states’ reports on their implementation of the UN POA are one of the main sources of data that will be used to measure its attainment. However, generating meaningful data on illicit arms flows is a challenging task and the amount of information submitted by states to date has been limited. This backgrounder provides an overview of ongoing and potential work on measuring states’ achievement of goal 16.4. It begins by outlining the SDG process and how it has sought to overcome the challenges associated with measuring illicit arms flows. It then summarizes the data collection efforts to date and outlines some possible options for filling the gaps that exist. 


The SDG indicators process

The 2030 sustainable development agenda is grounded in the idea that ‘there can be no sustainable development without peace, and no peace without sustainable development.’ The goal most closely associated with peace, SDG 16, promotes peaceful and inclusive societies for sustainable development, access to justice for all, and strong, effective and accountable institutions at all levels. It is considered one of the most ambitious and challenging of SDGs. Despite the prominence that SDG 16 gives to peaceful societies, only one target—16.4—directly references militarization and weaponry by committing states to inter alia ‘significantly reduce illicit arms flows by 2030’. The decision to focus only on illicit arms flows is due in part to state sensitivities about linking reductions in military spending to development. However, tracking illicit arms flows is not without its own challenges.

First, there is no universally agreed interpretation of the phrase ‘illicit arms flows’. Many states would argue that an illicit arms transfer is one that has not been approved by both the exporting and importing state. However, others—particularly the United States—have blocked the inclusion of this definition in relevant international instruments, largely because they wish to retain the option of supplying arms to rebel non-state actors. Second, the different international and legal instruments that seek to address the challenges presented by the illicit arms trade do not provide a unified and coherent definition of which ‘arms’ should be included in such a data collection effort. At the UN level, separate processes have been established that provide definitions of ‘conventional arms’, ‘small arms’ and ‘firearms’, all of which could potentially form the basis of national data collection efforts. Third, the act of collecting and analyzing any data on illicit arms flows is—by its very nature—challenging. The illicit arms trade typically involves concealed activities, and thus is very difficult to measure directly. This may be particularly true for states with limited resources who may be especially affected by the negative consequences of the illicit arms trade.

Indicators are being developed for every SDG in the 2030 Agenda at the global, regional, national levels, in addition to a fourth category of thematic indicators on selected cross-cutting issues. Global indicators, which apply to all states, are developed and managed by the Inter-Agency Expert Group on SDGs (IAEG-SDG). In order to measure the illicit arms component of SDG 16.4 the UN Statistics Commission has adopted Indicator 16.4.2 which the IAEG-SDG has defined as the proportion of seized, found or surrendered arms whose illicit origin or context has been traced or established by a competent authority in line with international instruments’. With this definition, Indicator 16.4.2 takes an indirect approach to measuring illicit arms flows, drawing on information provided on the implementation of international arms control measures, and harnessing the synergies among these measures to generate better data. However, it is widely recognized that Indicator 16.4.2 is far from perfect. It was initially classed as a ‘Tier II indicator’ by the UN Secretariat, it was later reclassified as a Tier III indicator. This means that ‘no internationally established methodology or standards are yet available for the indicator, but methodology/standards are being (or will be) developed or tested.’

The UN Office for Disarmament Affairs (UNODA) and the UN Office on Drugs and Crime (UNODC) have both been named as custodian agencies of Indicator 16.4.2. by the IAEG-SDG. This means they are responsible for ensuring that national data are comparable, producing regional and global aggregate figures, submitting data for the global SDG database, and helping states establish effective data collection tools. The UNODA is responsible for overseeing states implementation of the UN POA while UNODC is responsible for overseeing states' implementation of the UN Firearms Protocol. Both agencies have launched data collection efforts that are tied to the mechanisms through which states report on their implementation of these instruments.


Measuring indicator 16.4.2

The UNODA began collecting data for indicator SDG16.4.2 in 2017 by making adjustments to the set of questions on SALW seizures in the reports states are asked to submit on their implementation of the UN POA. The UN POA is a politically binding instrument that was adopted in 2001 and outlines steps that should be taken at the international, regional and national level to counter the illicit trade in SALW ‘in all its aspects’. States are encouraged to report on their implementation of the UN PoA every two years and to do so using an online reporting template developed by UNODA. The reporting template was amended by adding an expanded set of questions on SALW seizures. States that complete the questions fully will be providing data on how many SALW have been ‘seized’, ‘found’ or ‘surrendered’ and in how many cases an attempt was made to trace their origin. While this would not reveal how many of the SALW have had their ‘illicit origin or context … traced or established’—as is required under SDG 16.4.2—it would provide information on what steps had been taken to achieve that aim.

States were asked to submit their 2018 reports on their implementation of the UN POA by the end of January and—to date—109 states have done so. This is significantly higher than 2016, when 89 states submitted reports and close to the level achieved in 2008 when a record 111 states submitted reports (see table 1). Of these 109 states, 66 reported that they had collected SALW in 2016 or 2017 and 43 provided data on the numbers involved. This again represents an increase on 2016, when 41 states reported that they had collected SALW and 21 provided data on the numbers involved. However, only ten states provided data on the number of tracing requests initiated, the figure needed for indicator 16.4.2. Six states (Burundi, Chile, Congo (DRC), Estonia, Kenya and Australia) stated that no tracing requests were initiated while Botswana reported 11, Peru reported 5, Serbia reported 25 291, and the United Kingdom reported 2277.

Table 1

Number of national reports submitted on POA implementation
2002 2003a 2004 2005a 2006b 2007 2008a 2009 2010a 2011 2012b 2013 2014a 2015 2016a 2017 2018b
16 99 41 103 62 36 111 9 107 12 84 3 76 7 89 0 108

a A biennial meeting of states took place in these years.

b A review conference took place in these years.


A closer examination of the reports states submitted might reveal additional data on collected SALW that could have been reported. For example, in its report Spain stated that no SALW been collected in 2016 and 2017. This is despite the fact that in May 2017 the Spanish police reported that they had seized over 10 000 illicit assault rifles, anti-aircraft machine guns, shells and grenades. In addition, Mexico reported that 87 328 SALW had been seized, confiscated or collected in 2016 and 2017 but did not report that any tracing requests had been issued for these weapons. However, the US Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) reported that it processed 13 452 tracing requests for firearms recovered in Mexico in 2016. It is possible that these seizures and tracing requests were not included in Spain and Mexico’s national reports because of how these states have interpreted the coverage of the UN POA. For example, Spain may have not reported this seizure because it viewed the weapons as ‘firearms’&nbspand—therefore—not covered by the scope of the POA. However, making such an assessment would require states to report on how they have interpreted the different reporting categories, something the online reporting template does not request.

The UNODC began collecting data for indicator SDG16.4.2 in 2018 by issuing a new questionnaire on states’ implementation of the UN Firearms Protocol. The UN Firearms Protocol is a legally binding instrument—also adopted in 2001—that provides a framework for states to control and regulate licit firearms and firearms flows and prevent their diversion into the illicit market. To date, the UN Firearms Protocol has 164 signatories and 114 states parties and an additional 52 signatories. In 2015 UNODC published the first comprehensive assessment of states’ implementation of the UN Firearms Protocol, drawing upon completed questionnaires responses from 48 states. In May 2018, the UNODC published a new questionnaire for measuring states’ implementation of the UN Firearms Protocol. According to UNODC, one of the main goals of the questionnaire is to support the global monitoring of ‘the achievement of target 16.4 of the Sustainable Development Goals and its indicator 16.4.2 by UNODC.’

With regards to the information requested on Indicator 16.4.2 there are several differences between the UNODC questionnaire on the implementation of the UN Firearms Protocol published in May 2018 and the UNODA template for assessing implementation of the UN POA published in 2017. The main difference is that a far greater level of detail is requested in the UN Firearms Protocol questionnaire. In particular, the questionnaire contains detailed separate sections on seized, found and surrendered arms and the number of tracing requests initiated and their outcome. In another distinction from the UNODA data collection effort, states are also asked to specify how they interpret many of the key terms that are used in the questionnaire. States have been asked to send their completed questionnaires by the end of July 2018.



The more detailed questionnaire issued by the UNODC has the potential to produce more comprehensive data than has been generated to date by states’ submissions on their implementation of the UN POA. Moreover, the requirement for states to specify how they have interpreted key terms should mean that it will be easier to interpret any gaps in states’ submissions. However, the greater detail required in the UNODC questionnaire could also mean that even fewer states produce full responses. As the response rate to the UNODA questionnaire shows, collecting and reporting data on seizures is challenging for many states. Data is likely to be collected by a range of national authorities meaning that any records that are kept are likely to be widely dispersed and maintained using different standards. As noted, both UNODA and UNODC have a mandate to assist states with their data collection efforts—and both have committed to do so. Such efforts will hopefully help to close reporting gaps.

Also essential is that any data that is produced by states’ reports on their implementation of the UN POA and UN Firearms Protocol should be effectively analyzed and interrogated to ensure that any inconsistencies are uncovered and understood. However, the amount of work done on analyzing states’ implementation of such instruments has dropped in recent years. For example, the detailed analyses of states’ implementation of the UN POA have not appeared in recent years, raising questions about the purpose of states data collection efforts. Recent efforts by the Small Arms Survey point to a possible reversal in this trend but it is clear that significant work will need to be done. However, an accurate measuring of Indicator 16.4.2 will require drawing upon multiple sources of information. This will include both reports on states' implementation of the UN POA and UN Firearms Reports but also other sources of information, such as reports by Conflict Armaments Research and UN arms embargo panels of experts on seized and traced illicit weapons. It will also require following up with states to better understand any inconsistencies and to fill any remaining gaps.

Finally, the attention paid to states’ reports on their implementation of the UN POA and UN Firearms Protocol should not obscure the fact that Indicator 16.4.2 remains a very indirect means of measuring the attainment of goal 16.4. There is widespread recognition that an accurate measure of progress in achieving SDG 16.4 will require that these data collection efforts are supplemented by the development of national and regional level indicators, including to measure changes in illicit arms flows over time. The efforts that have been undertaken to date should be developed and expanded in order to ensure the generation of more robust data. In sum, much work remains to be done in defining these indicators and improving information on illicit arms flows before 2019, a pivotal year when progress made towards SDG 16 will be reviewed in depth at the High-Level Political Forum.


SIPRI intern Lukas Pashalidis carried out background research in support of this paper.


Dr Mark Bromley is a Senior Researcher with the SIPRI Dual-Use and Arms Trade Control Programme.
Dr Marina Caparini was until recently a Senior Researcher and Director of the SIPRI Governance and Society Programme.