This article argues that the principle of judicial economy belongs to the fundamental canons of international procedure – that is, those canons which are inherent in the judicial function and whose application should generally be ensured by the judge concerned, regardless of what the written procedural law establishes. This is particularly evident if one considers how often international courts and tribunals, precisely for reasons of judicial economy and departing from the duty to decide all points put forward by the parties (non ultra petita), enter into those issues alone which are necessary for the purpose of resolving the dispute and/or establishing the true state of the world (the so-called criterion of judicial limitation of the scope of the decision or absorption). Even though no provision requires it, each judge is in fact expected to operate in conformity with this criterion and to use it in a proper way; its misapplication may lead to reforming the decision or precluding its enforcement. The frequent use of the criterion at issue, on the other hand, supports this article's final contention, according to which judicial economy is an expression of judicial activism.

For decades it has been authoritatively stressed that non-justiciability of defence and foreign affairs represents one of the major hurdles to the application of international law by domestic courts. Until now, however, international law scholarship seems to have overlooked two aspects of this issue. First, it has not been sufficiently highlighted that the international and the European community legal orders are progressively eroding the scope of application of these non-justiciability doctrines. Second, it has rarely been shown how judicial intervention in international matters can be prevented from turning into the ‘judicialization’ of foreign policy. Hence, ideally by moving along the path traced by those who have already dealt with this issue, the present work aims to analyse these two aspects in greater depth.