Vanderbilt Journal of Transnational Law


Jan Klabbers

First Page



Under Article 18 of the 1969 Vienna Convention on the Law of Treaties, states that have signed or ratified a treaty are supposed to refrain from acts which might defeat the object and purpose of the treaty pending its entry into force. After noting that international lawyers and academics have recognized various types of treaties, the Article begins by observing that traditionally the interim obligation operates well in contractual situations but not in normative situations. Furthermore, the Author argues that where treaties are normative, the traditional conception of the interim obligation is insufficient.

While the interim obligation has been recognized in various international legal systems, it remains unclear how to determine whether the interim obligation is being violated. Several tests have been proposed, including evaluations of the subjective intent of the alleged infringing party and the legitimate expectations of the aggrieved party. The Author contends that none of the existing tests is adequate. Rather, he proposes the possibility of a "manifest intent" test. The manifest intent test has the advantage of being relatively objective, avoiding the pitfalls associated with more subjective tests. In addition, the manifest intent test is more appropriate in normative, non-contractual situations. The Author finds support for this test in the preparatory works for Article 18, as well as in both judicial practice and scholarly works.