Modalities of implementation

Generally speaking, in the second half of the twentieth century domestic systems gradually opened the door to international values and States became increasingly willing to bow to international law. Although each State is free to choose its own mechanisms for implementing international rules, even a cursory survey of national legal systems shows that two basic modalities prevail.

The first is automatic standing incorporation of international rules. Such incorporation occurs whenever the national constitution, or a law (or, in the case of judge-made law, judicial decisions) enjoin that all State officials as well as all nationals and other individuals living on the territory of the State are bound to apply certain present or future rules of international law. In other words, an internal norm pro­vides in a permanent way for the automatic incorporation into national law of any relevant rule of international (customary or treaty) law, without there being any need for the passing of an ad hoc national statute (subject to the exception of non-self-executing international rules). It follows that any time a treaty is duly approved and published in the State's Official Gazette or a customary rule of international law evolves in the world community, State officials and individuals must ipso facto and without further ado comply with it. This mechanism, among other things, enables the national legal system to adjust itself continuously and automatically to international legal standards. As soon as an international rule comes into existence, a corresponding legal provision evolves in the national legal system (subject to publication of the treaty, in the case of this category of international norms). By the same token, as soon as an international rule is terminated or changes in content, corresponding modifications in the national legal system take place (again, in the case of amendment of treaties, subject to publication of the amending provisions).

The second mechanism is legislative ad hoc incorporation of international rules. Under this system international rules become applicable within the State legal system only if and when the relevant parliamentary authorities pass specific implementing legislation. This legislation may take one of two principal forms. First, it may consist of an act of parliament translating the various treaty provisions into national legislation, setting out in detail the various obligations, powers, and rights stemming from those international provisions (statutory ad hoc incorporation of international rules). Second, the act of parliament may confine itself to enjoining the automatic applicability of the international rule within the national legal system, without reformulating that rule ad hoc (automatic ad hoc incorporation of international law). Under this second modality in substance the mechanism works in a similar way to the one that we have termed above 'automatic standing incor­poration' (the only difference being that now the incorporation is effected on a case-by-case basis). Now as well. State officials, and all the individuals concerned, become duty-bound to abide by the international provisions to which the act of parliament makes reference. The enabling legislation simply consists of one or two provisions stating that the treaty at issue must be complied with; the text of the treaty is annexed as a schedule. Courts, State officials, and individuals must infer the various provisions to be applied at the national level by way of interpretation. That is, these bodies or individuals must deduce from the text of the treaty, to which the piece of legislation refers, all the various rules to be applied at the national level.

For the purpose of ensuring a more complete and effective implementation of international law, preference should always be given to the legislative ad hoc Incorporation of international rules whenever they turn out to be non self-executing. Conversely, whenever international rules are self-executing, it would be preferable to resort to the automatic (whether permanent or ad hoc) incorporation of international rules. Indeed, this mechanism better safeguards the correct application of international rules because it does not ossify them: instead, it enables the national legal system to adjust itself fully to international rules as they are construed and applied in the international sphere.