Evolution of the Norm against Chemical Weapons

The use of poison is as old as humankind. Likely, humans used poison first as a force multiplier when hunting big game before it became a weapon of combat. Ancient writings clearly indicate that societies were ambivalent about the use of poison in combat. The first written statements against the use of poison and poisoned weapons in combat expressed a particular society’s moral values. The oldest known document is the Manusmrti (the Tradition of Manu). It was compiled in the second or first century BCE and forms one of the foundations of Hindu code. Religions have had a restraining influence on the conduct of war and on the use of poisons in particular. Neither the Old and New Testaments nor the Qur’an discuss poisoning and consequently do not contain any formal prohibition. The origins of contemporary laws of war can be traced to the teachings of the Prophet Mohammed in the 7th century and the influence of Christianity and chivalry on the conduct of war in the Middle Ages. Because of the diaspora, Jews did not engage in organised warfare until the foundation of Israel in 1948. As a consequence, Judaism never developed similar religious constraints on poison warfare.

From the Renaissance onwards, many European legal scholars stimulated the discussion of constraints on warfare. They testified to certain practices that either were or ought to be banned. Poisons were invariably among the weapons they considered unlawful. Certain military formations, as well as armies from emerging sovereign states, began adopting such prohibitions as part of their code of conduct. However, these unilateral expressions of behaviour on the battlefield did not bind other civilisations or political entities.

In the 19th century, the sovereign state established itself as the dominant form of social organisation, which increased the opportunities for international treaties. Furthermore, industrialisation and technological innovation rapidly changed the nature of warfare, as a consequence of which the leading powers began codifying the customs of war. In 1899, they convened in The Hague for the first Peace Conference. There they concluded two multilateral agreements. The Hague Convention (II) codified the customs and laws of war. It included the age-old ban on the use of poison and poisoned weapons. The second document, the Hague Declaration (IV,2) prohibited the use of asphyxiating or deleterious gases. This was the first time that asphyxiating gases became separated from poison, a clear reflection of the growing impact of science and industrialisation on future warfare.

These agreements did not prevent the use of asphyxiating gases in the First World War. After the Armistice in 1918, the League of Nations looked into banning chemical weapons. This resulted in the Geneva Protocol of 1925, which is still in force today. Diplomats, however, intended this document to lay the foundation for a comprehensive disarmament treaty. The failure of the League of Nations’ Disarmament Conference in the 1930s meant that the Geneva Protocol remained the only restriction on chemical weapons until the Chemical Weapons Convention entered into force in 1997.

The Chemical Weapons Convention is a global, multilateral treaty that bans the development, acquisition, possession and use of chemical weapons. Negotiations were concluded in September 1992, and the document was opened for signature in January 1993. It entered into force on 29 April 1997.

The Chemical Weapons Convention established the Organisation for the Prohibition of Chemical Weapons or OPCW. Every state party to the CWC is a member of the OPCW. The OPCW is based in The Hague, The Netherlands. It oversees the implementation of the treaty provisions and ensures that all states remain compliant with their obligations. It is an independent body and not part of the family of United Nations organisations.

The OPCW is a forum where state parties meet and decide both on implementation strategies and the practical management of the treaty. It also has a Technical Secretariat with an international inspectorate and specialised staff. In addition, several subsidiary bodies inform decision-making, the most prominent one being the Scientific Advisory Board, which monitors and regularly reports on the impact of science and technology on the CWC, or addresses technical questions put to it.

General Purpose Criterion

Chemical warfare agents have often been toxic industrial chemicals in widespread use, or their production rested on commonly used chemicals, known as precursors. Banning chemical weapons, therefore, requires the control of dual-use technologies, which have legitimate applications but can also be used for weapon development. The CWC addresses the dual-use challenge by means of the so-called General Purpose Criterion. In essence, the CWC does not ban chemicals, but the goal to which they may be applied.

For example, in 2015, global annual production of chlorine exceeded 60 million tonnes, up from 44 million tonnes 20 years earlier. The CWC does not interfere with its legitimate production and trade, despite it having been the first toxic chemical used on a large scale in the World War I. However, following confirmation of the repeated use of the toxic chemical as a weapon in the Syrian civil war, the OPCW condemned the use of chlorine as a method of warfare in February 2015.

The General Purpose Criterion offers another advantage. Because the prohibition on chemical weapons is not specific to certain chemical compounds, it also covers any toxic chemical that will be discovered in future. In other words, it allows the Chemical Weapons Convention to remain relevant in view of scientific and technological developments.

Verification

The CWC has a declaration-based verification system. First, a state party must declare any chemical weapons it possesses, which are verified by the Technical Secretariat and then destroyed under its supervision. Second, a state party must declare the industrial production of toxic chemicals.

The existence of the OPCW, however, does not mean that individual state parties have no responsibilities under the CWC. Quite the contrary, the CWC foresees a division of labour between the Technical Secretariat and the state party.

Each state must establish a National Authority, which liaises between a state party’s government and the Technical Secretariat, as well as with National Authorities of other state parties.

The principal task of the National Authority is to collect all relevant information from civilian and military facilities whose activities fall within the scope of the CWC and report the data to the Technical Secretariat. The National Authority also acts as a contact and host for the international inspection teams entering the country. Much of the effectiveness of the verification system actually depends on the effectiveness of the national systems.

Compliance

Declarations by state parties on CWC-related activities and national implementation of certain treaty provisions, including the need for national implementation legislation, form the foundation for compliance.

Any unreported or erroneously reported activity is a violation of CWC, but the violation is not necessarily deliberate and can be easily remedied. To address anomalies of a more serious nature, the CWC foresees consultations between the Director-General of the OPCW and a state party or between state parties, formal clarification requests, and challenge inspections. The Technical Secretariat can also investigate allegations of use of chemical weapons, as has been the case during the Syrian civil war.

Given that the CWC is essentially a cooperative security regime, the preference is clearly for resolving anomalies at the lowest level of confrontation.