The Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction (BTWC) is the principal international legal instrument against biological warfare. The BTWC was opened for signature on 10 April 1972 and entered into force on 26 March 1975. As of March 2008, 161 states have ratified or acceded to the BTWC.

The BTWC comprises 15 articles.

Prohibition to acquire or stockpile biological weapons

At the heart of the BTWC regime lies the disarmament obligation of Article I, which specifies that states parties cannot acquire or retain biological weapons (BW) under any circumstances. The Fourth Review Conference of States Parties, held in 1996, formally expanded the interpretation of this article to cover the use of biological weapons (BW).

The core prohibition is reinforced by the requirement in Article II to destroy or divert all BW to peaceful uses and by the non-proliferation provision of Article III. Article IV obliges States Parties to transpose these obligations into national laws and regulations so that the prohibitions also become applicable to natural and legal persons.

In 2004 the UN Security Council adopted Resolution 1540 to prevent non-state actors from acquiring unconventional weapons. The text basically follows the obligation contained in Article IV of the BTWC. This means that even States not party to the BTWC must adopt national legislative measures to prevent the misuse of biology and biotechnology for hostile purposes.

Compliance and consultation

The BTWC is the first disarmament treaty ordering the elimination of an entire category of weapons and prohibiting future efforts to develop, produce and stockpile BW. The document was negotiated and entered into force during the Cold War. Among the consequences of the superpower rivalry was the inability to agree on a set of verification measures and the establishment of an international organisation to oversee the implementation of the treaty.

The convention contains some tools to deal with compliance concerns. Under Article V parties may consult and cooperate with each other to resolve an issue or may undertake to resolve the concern through appropriate international procedures within the framework of the United Nations and in accordance with its Charter. The Third Review Conference (1991) adopted a procedure to strengthen Article V, whereby bilateral or other consultations among the states involved in a dispute must precede the formal consultative meeting. The depositaries of the BTWC must convene such a formal consultative meeting within 60 days following the receipt of the request to hold such a meeting. Any compliance concerns that cannot be resolved through consultation and cooperation may be referred to the UN Security Council, in accordance with the provisions of Article VI. In such a case, the BTWC parties are enjoined to cooperate with the Security Council during its investigation. The results of the investigation are to be conveyed to all BTWC parties. No party has ever lodged a complaint of a suspected violation of the BTWC with the UN Security Council.

International cooperation for peaceful purposes

Another cornerstone of the BTWC is Article X, which gives the parties the right to participate in the fullest possible exchange of equipment, materials, and scientific and technological information of relevance to the convention for peaceful purposes and encourages the parties to facilitate such exchanges. The article also orders states parties to implement the BTWC in such a way that it avoids hampering the economic or technological development of states parties.

Article X has become more contentious as biotechnology plays an increasingly dominant role in economic and societal development but may also make it easier for a state to acquire an offensive biological warfare capability (e.g., in terms of a surge production capability for BW) or to develop novel types of agents. Its implementation must therefore also be consistent with the non-proliferation obligation in Article III.

The controversy has receded over the past years as States Parties have engaged in in various bilateral or inter-regional cooperative programmes, identified new areas of possible cooperation relating to the promotion of biotechnology and the prevention of the misuse of biology and biotechnology, the need for international cooperation in the combat of emerging and re-emerging diseases, and the growing realisation that no society is immune from the dangers of terrorism and international crime, which might involve the release of pathogens or toxins.

Review conferences and inter-sessional meetings

Despite its intrinsic weaknesses the BTWC has been able to retain its relevance through the periodic review conferences, during which the parties interpret the treaty provisions in the light of political and technological developments or try to devise mechanisms to enhance confidence in the treaty regime.

Among the major contributions to the development the treaty regime through the review conference process are the extension of the core prohibition in Article I to BW use, the development of Confidence Building Measures (CBMs), the amelioration of the consultation procedure in case of compliance concerns, and, since 2001, the organisation of annual meetings to exchange information and discuss specific issues relating to the implementation of the BTWC. At the 6th Review Conference (2006), the States Parties decided on the establishment of an Implementation Support Unit to accompany the annual meetings.