Introduction: the allocation of functions between the judiciary and the executive

The role of the judiciary in the Anglo-Commonwealth countries in foreign relations matters may be restated as a set of implications from the general principles of the distribution of powers and the rule of law. As David Mullan has recently written, there is a need for the ‘normalisation’ of the review of high executive powers, since ‘arguments for retrenchment or withdrawal to previous strongholds have little leverage either constitutionally or from the perspective of institutional competencies’. Put within the framework set forth in this book, this means that it is necessary to consider the allocation of the foreign affairs power between the institutional competencies of the respective organs of government and the manner and extent to which each organ may, in the exercise of its institutional competency, maintain a check and balance on the power of the other.

It is the burden of this chapter to analyse the movement of the law from an apparently absolute position in which foreign affairs were taken as being solely within the province of the executive and outside the province of the judiciary altogether. Originally, as was seen above in Chapter 2, this position was said to derive from the source of the power in the prerogative. Even after the courts rejected the source theory, they continued to assert that foreign affairs fell into a specific class of cases where the courts could not tread. That notion is often expressed, even today, under the catch-all phrase of ‘non-justiciability,’ or, in American terms, ‘political question’. But, convenient though the notion of non-justiciability has proved as shorthand, it obscures more than it illuminates.