The constitution and foreign affairs

This article examines a dimension of public law which, despite the increased frequency of litigation in this area, remains relatively under-explored: the constitution and foreign affairs. To aid this task, two models are elaborated. The first, the unilateralist or sovereigntist model, assumes a sharp separation between the internal and the external as domains of peace (constitution), and war (reason of state) respectively. The second model assumes that juridical boundaries are contested and permeable, reading the dynamics of constitutional development in terms of a process of mutual recognition. While the former may have had more historical traction, I argue that the latter now provides the better guide, both analytically and normatively. The theoretical argument is developed in relation to the lived tradition of the British constitution. The article closes with a series of propositions that seek to capture the emerging principles within this complex and fast-moving area of law.