- Vienna Convention on the Law of Treaties — Effectiveness, principle of
Under Article 18 of the 1969 Vienna Convention on the Law of Treaties, a State which has signed or ratified a treaty has the obligation to refrain from acts which would defeat the object and purpose of that treaty prior to its entry into force. Vagueness and ineffectiveness are often indicated as the two major shortcomings affecting the obligation laid down in Article 18. This chapter assesses whether such criticism is justified. More comprehensively, it endeavours to reassess the impact Article 18 has had on State practice over the forty years since the adoption of Vienna Convention. Its major finding is that, while Article 18 seems to suffer from certain shortcomings, which inevitably weaken its normative force, it is by no means a rule devoid of any practical relevance, particularly if one takes into account the increasing recourse to this provision in cases before domestic courts.