The First World War left millions dead on the battlefields of Europe, and the survivors returned home with the experience of the first industrial‐style war fresh in their minds. It was particularly because of the horrors created by the use of chemical weapons and the mutilation that these gases caused that the main players in the war started to consider a widespread ban on such methods of attack. After several years of negotiations, on 19 June 1925, the major industrialized countries signed the protocol for the ‘Prohibition of the Use of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare’ in Geneva, which is now known as the Geneva Protocol. But less than 20 years after its creation, this protocol did not prevent some contractors of the treaty from engaging in offensive biological warfare programmes. Furthermore, the development and use of biological weapons by Japan in the Second World War led to an expansion of these programmes in various Western countries and in the Soviet Union. In the 1960s, Western countries started to critically assess their biological weapons programmes because of technical problems in the production and storage of the agents involved. In addition, it became clear that biological weapons are of limited military use because they pose a considerable risk to the attacker as well as to the attacked. The USA and the UK therefore concluded that the size of their existing conventional, chemical and nuclear weapon inventories was sufficient to retaliate against a Soviet attack and that biological weapons were no longer required. This conclusion eventually culminated on 10 April 1972 with the signing of the ‘Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction’ (BTWC) (www.opbw.org) that entered into force in 1975. However, rumours …