Under Article X of the Biological Weapons Convention (BWC), States Parties commit to facilitate and have the right to participate in the fullest possible exchange of equipment, materials, and information for peaceful purposes. This article appears to have received limited attention in the negotiation of the BWC. However, since the late 1960s and early 1970s, expectations of the BWC States Parties not only to avoid “hampering” but to actively promote international cooperation have become much more significant, to the extent that measures to enhance international cooperation under Article X have become a prerequisite for the wider strengthening of the Convention. This chapter starts by exploring the origins and evolution of Article X of the BWC, looking both at external developments in the international sphere that influenced the debates, as well as the interpretations and text of the additional understandings agreed over the course of half a century of BWC meetings. The chapter then provides an overview of current activities conducted outside of the BWC framework. It concludes with a discussion on the prospects for advancing international cooperation under Article X in the current context and, in the process, strengthening the BWC over the next 50 years.