Legitimacy and effectiveness of provisionally applied treaties between international and domestic law

While provisional application emerged as an instrument for solving crises and complexities, its functioning is not as simple as may appear at first sight and the notion of provisional application itself entailed several theoretical and practical debates. Notwithstanding a long-standing and widespread practice, the theorization and conceptualization of provisional application of treaties encountered first of all the difficulty of legally defining an anomalous institute. The most controversial issues regard, on the one hand, the legitimacy of provisionally applied treaties at the domestic level and, on the other hand, their effectiveness in the international sphere. As to the legitimacy of provisional application, it is crucial to evaluate the compatibility of such practice with the domestic rules concerning the competence to bind States internationally. As to the effectiveness of provisionally applied treaties, instead, it is necessary to assess their legal nature and validity regime under international law. The following analysis attempts to shed light on these issues, investigating the provisional application's legitimacy under domestic law and its impact on the legal validity of provisionally applied treaties under international law.