A decade of evolution in the international law of WMD

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This article is intended to provide an overview of how the past decade of implementing UN Security Council resolution (UNSCR) 1540 has impacted the development of an international law of weapons of mass destruction (WMD). After briefly discussing the legal status of the resolution, I will attempt to identify key elements of this field of international law that are derived from or supported by 1540. Finally, I will offer some few suggestions for further approaches to strengthening and consolidating this legal regime.

Scope of UNSCR 1540

A threshold issue regarding the analysis of any legal instrument is to determine the scope of activities to which it applies. How to define weapons of mass destruction has itself been debated over many decades since the archbishop of Canterbury—apparently the first to use the term—applied it to the 1937 bombardment of Guernica in the Spanish Civil War. I do not propose to offer a precise definition of the term “international WMD law.” UNSCR 1540 itself does not define WMD. This parallels the failure to define “terrorism” in many of the international anti-terrorism instruments.

The term WMD is used in UNSCR 1540 only once—in its preamble reaffirming the 1992 statement of the Council’s President. Otherwise, the resolution speaks of a trilogy of technologies—nuclear, chemical, or biological weapons. The conflation of these three weapons technologies is of some interest, given their disparate character and histories. Of the three, chemical weapons are arguably the oldest. There is evidence that poisons and asphyxiating agents have been employed in warfare since antiquity. Biological weapons came later, perhaps as early as the middle of the eighteenth century, when a British general suggested that smallpox-infected blankets be distributed to attacking tribesmen at the siege of Fort Pitt (later Pittsburgh, USA). And nuclear weapons were not used until 1945 in the bombings of Hiroshima and Nagasaki in Japan. (For a detailed discussion of the origins and usage of the term WMD, see Q. Michel, ed., in Controlling the Trade of Dual-Use Goods—A Handbook, Brussels, 2013, pp. 15-23). UNSCR 1540 also excludes various technologies or practices that some might characterize as WMD, such as massacres or bombardment of civilian populations with conventional explosives or even forced starvation. Since these and other measures are proscribed by international humanitarian law, the drafters of UNSCR evidently felt no need to include them. More importantly, the narrower scope of 1540 reflects its focus on the threat that these particularly dangerous weapons might be acquired and used by non-state actors, rather than by states in warfare.

Although some WMD technologies have a lengthy history, efforts under international law to restrain their use are relatively recent. This legal history precedes the adoption of UNSCR 1540 in April 2004 by many decades. This article will not attempt to cite all relevant instruments, declarations and resolutions, but they certainly include the following key treaties and conventions: the 1925 Geneva Protocol to the Hague Conventions banning chemical and biological warfare; the 19678 Treaty on the Non-Proliferation of Nuclear Weapons (NPT); the 1979 Convention on the Protection of Nuclear Materials (CPPNM) and its 2005 Amendment; the 2005 International Convention on the Suppression of Acts of Nuclear Terrorism (ICSANT); the 1972 Biological Weapons Convention (BWC); and the 1993 Chemical Weapons Convention (CWC).

Beyond these binding international instruments, a wide range of voluntary guidance documents has been developed that arguably contributes to the global legal framework for combating WMD proliferation. The author is particularly familiar with such guidance documents in the nuclear field. They include, but are—by no means limited to—the International Atomic Energy Agency (IAEA) Code of Conduct on the Safety and Security of Radioactive Sources; the growing number of documents in the IAEA Nuclear Security Series (NSS); IAEA Safeguards instruments; and various export control regimes such as the Nuclear Suppliers Group. In the field of chemical and biological weapons, the Australia Group has developed guidelines and common export approaches for these technologies.

Status of UNSCR 1540 in international law

The status of resolutions of the Security Council in international law is established by Chapter V of the Charter of the United Nations. By adhering to the Charter (an international treaty), UN member states agree to accept and carry out “decisions” of the Council pursuant to Article 25. Of greatest significance for interpreting UNSCR 1540, the Council adopted the resolution under Chapter VII of the Charter, which pertains to “Action with Respect to Threats to the Peace, Breaches of Peace, and Acts of Aggression.” Under Articles 39 and 41 of Chapter VII, member states have committed themselves to implement those portions of UNSCR 1540 designated as decisions. However, the resolution has a mixed legal status—some provisions being binding and others non-binding.

In this regard, another important legal aspect must be taken into account. This involves the possibility that certain non-binding provisions of the resolution, as well as measures taken by states to implement these provisions, may have attained the status of customary international law. The determination of whether a measure should be considered customary law is much debated. However, in general, a customary rule of international law has been recognized where there is a legally significant “practice common to a plurality of States.” (See M. Sørensen, ed., Manual of Public International Law, Chapter 3, pp. 128-143.)

In the decade since the adoption of UNSCR 1540, the global community has arguably adopted a range of common practices with regard to international WMD law, with a significant number conducted with a view toward complying with the resolution. These practices not only relate to the decisions set forth in OP  1-5 of the resolution, but to other actions the Council “called upon” to implement under OP  8-10. Thus, it is submitted that implementation of UNSCR 1540 as a whole has contributed significantly to the development of an international law of WMD, both under treaty law and customary law. (See “Repertoire of the Practice of the Security Council,” <http://www.un.org/en/sc/repertoire/faq.shtml>.)

Impact of UNSCR 1540 on international WMD law

As noted earlier, prior to adoption of UNSCR1540, a “proliferation” of international instruments and initiatives has addressed chemical, biological, and nuclear weapons. UNSCR 1540 has rightly been called a “landmark resolution.” (See O. Jankowitsch-Prevor, “A New Role of Industrial Operators in Trade in an Evolving Nuclear Export Control Regime: Beyond Legal Responsibilities,” in Q. Michel, Sensitive Trade—The Perspective of European States, Brussels, 2011, p. 24.) The question remains, what has 1540 added to the existing framework? The following discussion will seek to identify major elements of 1540 that have influenced the character of WMD law and its implementation.

“Universalizing” WMD law

At the outset, a fundamental point should be made. This lies in the Security Council’s ability to require all UN member states to implement decisions taken under Chapter VII of the Charter. By addressing the major elements of WMD law (as will be discussed), the Council has essentially “universalized” this field of law. (See P. Crail, “Implementing UN Security Council Resolution 1540: A Risk-Based Approach,” in Nonproliferation Review 13, no. 2 (July 2006): p. 357.) Although some few nation-states are not members of the United Nations, that number is vanishingly small. Thus, UNSCR 1540 consolidates the obligations or commitments under the broad range of WMD instruments, both binding and voluntary, making them applicable to all states, even those that have not adhered to the relevant instruments or documents.

Refrain from support to non-state actors

The primary focus of international WMD lawmaking prior to major terrorist events early in this century was on restraining the proliferation of WMD among nation-states. However, after the 9/11 terrorist incidents in the United States and those in other states, attention has turned increasingly to the threat that terrorists or criminal elements might acquire and use WMD. I have discussed elsewhere the emergence of nuclear security as the most active field of nuclear law. (See C. Stoiber, “Nuclear Security: Legal Aspects of Physical Protection, Combating Illicit Trafficking and Nuclear Terrorism,” in International Nuclear Law: History, Evolution and Outlook—10th Anniversary of the International School of Nuclear Law, OECD/Nuclear Energy Agency, Paris, 2010, pp. 219-242.)

In light of this history, a fundamental advance in international WMD law under UNSCR 1540 was to extend its scope beyond the conduct of nation-states to the WMD-related activities of non-state actors. A footnote in the resolution’s preamble identifies the non-state actor very broadly as an “individual or entity, not acting under the lawful authority of any State in conducting activities which come within the scope of this resolution.” These certainly include terrorists and terrorist organizations, criminals and criminal bodies, and even insiders who may violate their legal responsibilities. Operative Paragraph 1 establishes the basic obligation that all states must refrain from “any form of support” to non-state actors in the full range of WMD-related activities, from acquisition to use. Although a range of anti-terrorism conventions address this issue with respect to specific technologies and activities (such as particular modes of transportation), UNSCR 1540 broadens these prohibitions to the entire United Nations.

Develop effective national laws

Operative Paragraph 2 of UNSC 1540 builds on the prohibition against support for non-state actors in WMD activities , by requiring States to adopt laws prohibiting the full range of relevant activities. This provision recognizes that effective implementation of the obligations in the resolution can only be accomplished within the legal systems of nation-states. Given the international character of the WMD threat, it is important that these national laws be not only consistent with the relevant international instruments, but harmonized in a way that allows for efficient coordination of efforts to control WMD activities that may transcend national boundaries.

  • Establish domestic controls
  • Operative Paragraph 3 is the longest in the resolution, covering a range of domestic controls that states must take to prevent WMD proliferation. Specifically, four subjects are identified:
  • Accounting for and securing items in production, use, storage, or transport
  • Physical protection measures
  • Border controls and law-enforcement efforts
  • Export and transshipment controls, including financing and transport, with appropriate criminal or civil penalties

As indicated earlier, adopting these measures as a binding decision essentially universalizes these measures as part of an international WMD law—a significant advance.

Establish committee to monitor and support implementation

Operative Paragraph 4 does not directly supplement international WMD law, but is perhaps one of the most important provisions in UNSCR 1540 because it establishes an institutional structure for monitoring and supporting the implementation of the resolution. Over the past decade, the 1540 Committee has conducted a wide range of activities in support of WMD law that should not be underestimated. Although not precisely an enforcement mechanism, the range of activities conducted under the aegis of the Committee has contributed significantly to the ability of UN Member States to meet their obligations under the resolution. Since others have described these implementation activities, I will not attempt to detail them in this article. Basically, they involve the assembly of relevant documents related to WMD, assistance in legislative and regulatory development, and coordination with other bodies—international, national, nongovernmental, and professional—in strengthening implementation of UNSCR 1540. In this regard, the annual reports of the Committee are perhaps the best source for understanding the nature and scope of its work over the past decade. See, e.g., the latest report for 2013 in UN document S/2013/769, December 26, 2013.

A second provision in Paragraph 4 is also relevant for the development of WMD law. This provision calls upon states to provide reports on their implementation of the resolution. As discussed previously, the development of a customary law of WMD is based on identifying practices common to a plurality of states. The reports of states to the 1540 Committee thus constitute important evidence of such common practices and contribute to the development of WMD law in a very concrete manner. Further, the Committee’s development of its 1540 matrix on national implementation is an important means for assessing compliance with the resolution and the level of common practice. See website for the matrix at <http://www.un.org/en/sc/1540/national.../matirx.shtml>.

Mandatory reporting of violations

A significant development for international WMD law that is not contained in UNSCR 1540 is reflected in another Security Council resolution adopted in 2013. UNSCR 2118 sets forth the Council’s decision that member states shall immediately inform the Council of any violation of UNSCR 1540. This important requirement could be essential in enabling the Council and member states to respond to WMD proliferation events in a timely and effective manner.

Non-binding provisions

Moving beyond the five binding paragraphs, UNSCR 1540 contains significant non-binding provisions that also strengthen international WMD law. Paragraph 6 records the Council’s recognition that effective national control lists for WMD-related materials and commodities are important and calls upon member states to develop them at the earliest opportunity. Paragraph 7 recognizes the need of some states for assistance in fulfilling their 1540 obligations and invites other states to offer assistance when requested.

Paragraphs 8 through 10 set forth provisions in which the Council calls upon member states to take additional measures in support of the resolution’s objectives. Without going into the details of these measures, they include:

  • Promoting universal adoption of relevant WMD multilateral treaties
  • Adopting national rules and regulations to meet obligations
  • Enhancing multilateral cooperation to achieve the resolution’s objectives
  • Working with industry and the public on implementation of relevant laws
  • Promoting dialogue and cooperation on WMD proliferation
  • Taking cooperative action to prevent illicit trafficking

Although these measures do not, in themselves, establish new rules of WMD law, they can contribute to the development of such rules through the aforementioned customary law process.

Additional steps for strengthening international WMD law

The previous discussion has summarized the basic elements of the important framework of WMD law for global security. Although this discussion has identified a broad range of activities that contribute to the regime, consideration should be given to further legal approaches to strengthening its development and implementation. The 1540 Committee’s Annual Report for 2013 contains a lengthy set of recommended future actions in its Part IV, “Assessment of Progress and Future Perspectives,” pp. 12-16. Some of these steps (eighteen are summarized in paragraph 80) are relevant to the development of WMD law. Assistance in developing national laws and regulations is one of the most important measures. However, consideration might be given to additional measures explicitly focused on international WMD law.

An integrated course on WMD law

Reference has been made in this article to a number of legal education courses or schools that instruct relevant persons in fields related to international WMD law. The author is particularly familiar with those in the nuclear law field, among the most important being the IAEA’s International Nuclear Law Institute and the Organization for Economic Cooperation and Development (OECD)/Nuclear Energy Agency’s International School of Nuclear Law. In the chemical- and biological-weapons fields, similar activities are conducted by the Organization for the Prevention of Chemical Weapons (OPCW) and the World Health Organization. These activities contribute significantly to the broader understanding and application of WMD law. However, there is room for improvement along several lines. First, the offerings in these schools relevant to WMD are limited by the time available, since a range of other subjects must be covered. Second, because each focuses on only one of the relevant WMD technologies, these bodies do not consider cross-cutting legal issues, including possible conflicts or inconsistencies in the handling of the different technologies. Third, they typically focus only on existing legal measures rather than take a forward-looking perspective on how the regime might be improved.

One approach that could be considered is for the 1540 Committee to sponsor a course on international WMD law, perhaps at UN headquarters in New York. The course would draw its faculty from relevant international organizations (the IAEA, OECD/NEA, UNODC, UNODA, and the OPCW) and experts (both legal and technical) from national governments. A curriculum would need to be developed that would first discuss the basic technical aspects of the WMD threat, moving on to a discussion of the relevant individual WMD legal regimes (nuclear, chemical, and biological) and then continue further to discuss cross-cutting legal issues and approaches. Finally, it would be of interest for the course to consider “the way forward” in terms of strengthening and consolidating the WMD legal regime, possibly with suggestions for measures to be taken to implement UNSCR 1540, either through other international instruments or through relevant organizations and national governments.

International WMD law manual or handbook

As discussed previously, a large number of publications address various aspects of international WMD law. These not only include materials on the website of the 1540 Committee, but also publications of relevant international organizations, as well as those of academic institutions, nongovernmental organizations, and industry. Although these publications focus on relevant aspects of WMD law within their competence, they may contain material not relevant to WMD proliferation. Further, they typically address only one technology or one aspect of WMD proliferation. Therefore, a consolidated publication that could be used by the 1540 Committee and other relevant bodies—both international and national—in implementing WMD law would be a welcome addition to the literature. The 1540 Committee would be the logical body to propose such a publication and to convene representatives of other relevant bodies and other experts to determine the structure and content of such a publication. Printing the volume in all official UN languages (and perhaps others) would make it an even greater tool for assistance and instruction.

WMD law and security culture

An important development relevant for international WMD law is the increasing emphasis on security culture. Although resolution 1540 does not use the term, its binding decisions and non-binding recommendations cannot be effectively implemented in the absence of a strong security culture. The resolution’s preamble references the Code of Conduct on the Safety and Security of Radioactive Sources, which defines “nuclear security culture” as “characteristics and attitudes in organizations and of individuals which establish that security issues receive the attention warranted by their significance.” The 1540 Committee reports other activities relevant to establishing security culture, for example in the biosecurity field. Expanded activities by the Committee and other international and national bodies in the area of security culture can help foster customary international law rules that states should apply as part of international WMD law. Relevant steps in this regard would be to include language on security culture in the review and implementation reports of the 1540 Committee and review meetings of relevant international instruments. The range of security issues should also be included in assistance efforts, including training and assessment efforts. 


An extremely broad range of activities, institutions, and publications are relevant to assessing the current status of an international WMD law and possible ways for enhancing this important legal framework. This article has only attempted to identify the fundamental aspects of this field and to suggest some few options for additional work. What is clear is that the adoption and implementation of UNSCR 1540 over the past decade has played an extremely important role in consolidating and strengthening an international legal regime that is vital for maintaining global peace and security.

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