The Royal Society has a long-standing interest in countermeasures against biological weapons. Lord May of Oxford, President of the Royal Society, and Bruce Alberts, President of the US National Academy of Sciences, have joined together to express their support for biological weapons controls in a joint editorial published in Science on 8 November 2002 (Volume 298, page 1135). The editorial has been timed to coincide with the Reconvened Fifth Review Conference of the Biological and Toxin Weapons Convention, taking place in Geneva from 11 to 22 November 2002.