The degree to which the decisions of individuals matter in both the domestic and international policy domains is by no means a new debate within the field of International Relations, especially concerning matters of national security. In response to the perceived limitations of the then-dominant rational actor model of decision-making, the theoretical and empirical work of Robert Jervis and Irving Janis on personality and cognitive approaches to leadership and decisionmaking, suggested that individual biases and perceptions of reality do indeed play a significant role in the formation of state preferences.1 The more recent ‘policy entrepreneur’ literature, rooted in social constructivism, has also sought to illuminate the significance of individual political actors, specifically in relation to the advancement of norms informing global governance.