Provisional Measures in ICSID Arbitration. From “Wonderland’s Jurisprudence” to Informal Modification of Treaties

A long stream of substantially identical decisions rendered by ICSID tribunals, starting with Maffezini v. Spain, have upheld their power to order provisional measures under Article 47 ICSID Convention. Since Article 47 ICSID Convention expressly authorizes ICSID tribunals only to recommend such measures, it is worth examining the significance and implications of these decisions from the standpoint of the law of the treaties. The paper first offers a concise discussion of the nature and role of provisional measures in the settlement of international disputes before reviewing the leading cases of the International Court of Justice (ICJ) and other international tribunals (sections II to IV). It then briefly describes the emergence of what appears to be a jurisprudence constante in ICSID investment arbitration (section V) and examines the persuasiveness of the underlying legal reasoning (section VI). Section VII is consecrated to the attitude of ICSID membership with regard to these decisions. The final objective of the paper is to appraise the impact of the concordant body of decisions in combination with the (lack of) reaction of member parties to the ICSID Convention from the standpoint of the interpretation and possibly the informal modification of Article 47.