This thesis conducts an analysis of the Intersessional Process (ISP) of the Biological and Toxin Weapons Convention (BTWC) between 2001 and 2006. Specifically, it aims to assess the extent to which the ISP has resulted in progress towards strengthening the BTWC. The fulfilment of the research aim is derived from three discrete approaches: firstly, an assessment of problems and weaknesses faced by the Convention; secondly, an assessment of common or converging understandings around measures to respond to such problems and weaknesses; and thirdly, an assessment of what effective action has been achieved between 2001 and 2006. To achieve this, this thesis uses a framework that structures the assessment around four dimensions of the BTWC and their evolution within a changing geostrategic and scientific context. The four dimensions identified are compliance, development, institutional and research. The conclusions drawn from this thesis suggest that although the compliance dimension has made some considerable progress in the area of national legislation and biosafety and biosecurity, it remains clear that other areas of the compliance dimension remain underdeveloped and deeply divisive. The development dimension has also made progress over the course of the ISP and, significantly, achieved much greater convergence in its focus around disease surveillance and detection. However, changing dynamics in security and science have negatively affected other areas of the development dimension. In terms of the institutional dimension, there has been a modest progress with regard to the BTWC¿s institutional and procedural evolution; however, legitimate concerns remain in relation to quantity and quality of membership of the BTWC relative to other agreements. Finally, there has been some motion towards the emergence of a more coherent dimension of research; although certain advances in science research remain neglected in the BTWC forum, and the issue of biodefence has been conspicuously absent from discussion during the ISP. Based on the analysis conducted, this thesis argues that the BTWC has made cautious progress over the course of the ISP, and there is evidence of a convergence in responses and effective action in some areas. However, there is insufficient evidence to suggest there has been ¿major progress towards strengthening the Convention¿ and many issues require much greater attention.