It is vital to revisit how confidence in the Biological Weapons Convention (BWC) can be strengthened. To do that we need to ask challenging questions about what limits the relevance of Confidence Building Measures, and we need to identify what else is needed to establish and maintain confidence between states parties. This paper enables reflection on how those involved in the BWC process collectively assess issues affecting the convention. It focuses on the prevalence of defensive reasoning, which inhibits robust enquiry and encourages anti-learning practices. It argues that instead of more of the same, alternative types of discussions needed to be nurtured.